It was by no means certain the rescheduled Tokyo 2020 Olympics would even go ahead, such was the uncertainty caused by the coronavirus pandemic.

But go ahead they did and now here we stand on the eve of the closing ceremony in the Japanese capital.

They have certainly been a Games like no other and we all hope future Olympics will not be held under such unusual circumstances, and judging the success of Tokyo 2020 is no easy feat given the measures to do so are too arbitrary.

Having said that, here are the highs of the Games and some of the lows, too.

The highs…

WARHOLM AND MCLAUGHLIN HAMMER THE HURDLES

Karsten Warholm revelled in bringing the "wow" factor to the men's 400m hurdles, and rightly so. The Norwegian became the first man to break the 46-second barrier – running an astonishing 45.94 seconds to smash his own world record, five weeks after breaking a benchmark held by Kevin Young for 29 years. A day later, Sydney McLaughlin battered her own world record in the women's race, clocking in at 51.46s.

VAN VLEUTEN'S HEARTWARMING TRIUMPH

Five years ago in Rio, Annemiek van Vleuten was on course for victory in the women's cycling road race until a high-speed crash left her with minor fractures to her spine. To make matters worse, the Dutchwoman made headlines for celebrating what she thought was victory in the same event here in Tokyo – only to realise she had finished second behind runaway winner Anna Kiesenhofer. But finally, her golden moment arrived in the women's time trial – at the age of 38 years and 293 days, she became the third-oldest woman to win Olympic gold for the Netherlands.

SWIMMING STARS PROVE THERE'S LIFE AFTER PHELPS

Michael Phelps is an Olympics legend and no one can lay claim to more than the 23 golds or 28 overall medals he accrued over between 2004 and 2016. But a stellar cast this year proved swimming is in a very strong position. Emma McKeon took home seven medals (including four golds) – the joint-most of any woman at a single Games – while Ariarne Titmus' 200m and 400m free double was memorable, particularly her win over the great Katie Ledecky in the latter race. Caeleb Dressel took five golds to show his potential as Phelps' heir apparent, while Adam Peaty stunned again for Great Britain. It was some week in the pool.

THOMPSON-HERAH DOES THE DOUBLE-DOUBLE

Elaine Thompson-Herah announced herself to the world stage with a 100 and 200m sprint double at Rio 2016 but injuries in the intervening years stemmed her momentum a little. However, she peaked at the perfect time in Tokyo and backed up her double from Brazil – becoming the first woman to repeat on the 100 and 200m. Indeed, only Usain Bolt had ever previously done so.

THE AZZURRI'S GOLDEN HOUR

There was a shock in the men's 100m final where the unheralded Marcell Jacobs started the post-Bolt era with gold. That followed on from countryman Gianmarco Tamberi having minutes earlier shared high jump glory with Mutaz Essa Barshim. There were hugs aplenty as Italy, surely celebrating their greatest night at an Olympics, won two athletics golds at the same Games since Athens in 2004.

NEW EVENTS CATCH THE IMAGINATION

One of the most fascinating aspects of any Olympics is the new sports and categories that get added to the programme. At Tokyo 2020, skateboarding, surfing and climbing have all attracted new and younger audiences to the Games – while the addition of mixed triathlon and the mixed 4x400m track relay have been successes.

BILES' INSPIRATIONAL MESSAGE

On the one hand, the fact we saw so little of Simone Biles and some of the reprehensible bilge aimed her way over the decision to pull out of the women's team event after just one rotation and then miss four individual events can be seen as a negative. But, on the other hand, the fact that she came back to take bronze on the balance beam and use her platform to promote the importance of protecting mental health has to be seen as a high. It takes bravery and courage in her position to speak on such matters. Kudos to you, Simone.

And the lows…

EMPTY STADIUMS AN ENDURING IMAGE

Let's start with the obvious here and something that has been spoken about pretty relentlessly. The absence of fans has had a huge cost on the atmosphere at these Games. Magical moments and career peaks played out in front of huge, empty stadia has undoubtedly been a huge negative. Many will take the fact we got here and managed to hold a Games at all as a positive. And it is. But at times, the whole thing felt a bit… meh.

TENNIS' HEADLINE ACTS FAIL TO DELIVER

With so many of the top male players opting to skip Tokyo, there was a big focus on Novak Djokovic and the next checkmark on his quest for a rare Golden Slam (only Steffi Graf has ever done it). The Serbian fell short, dropping out at the semi-final stage then getting a little stroppy. Big things were also expected of Naomi Osaka – a home hope and the 'face of the Games'. She made it as far as round three before going down to Marketa Vondrousova.

THE TSIMANOUSKAYA SAGA

One of the ugliest stories to emerge from the Games was the story of Belarusian runner Krystsina Tsimanouskaya, who refused to board a flight after allegedly being taken to the airport against her will following her public criticism of her team's organisation on social media. Tsimanouskaya competed in only one event and claimed she was entered into a 4x400m relay despite never racing in the discipline, suggesting that was a result of members of the team being considered ineligible due to not completing enough doping tests. The Belarusian Sport Solidarity Foundation indicated Tsimanouskaya feared for her life upon returning to Minsk. The country is under the authoritarian leadership of president Alexander Lukashenko, whose son Viktor heads the national Olympic committee (NOC). Both men were banned last December from attending Tokyo 2020. The whole thing has been really rather unsavoury.

Simone Biles said she had put her "mental health first" after missing out on adding a fifth Olympic gold medal to her collection following an early withdrawal from the women’s team final.

The 24-year-old gymnastics icon revealed she was “dealing with things internally” after a disappointing performance on the vault.

Biles posted the lowest score of the first rotation on Tuesday as she landed awkwardly after failing to execute an Amanar, while only completing a Yurchenko 1.5 twist.

After she subsequently withdrew, Team USA had to settle for a silver medal behind the Russian Olympic Committee while Great Britain completed the podium.

Biles admitted that she was "fighting demons", explaining: "I just don't trust myself as much as I used to. I don't know if it's age. I'm a little bit more nervous when I do gymnastics. I feel like I'm also not having as much fun."

She added: "I say, 'put mental health first'. Because if you don't, you won't enjoy sport and won't succeed as much as you want to.

"So it's okay sometimes to sit out the big competitions to focus on yourself, because it shows how strong a competitor and person that you really are, rather than just battling through it."

OSAKA STUNNED

The big names continue to tumble in the women’s singles tennis event, with second seed Naomi Osaka defeated in straight sets.

The home favourite, who lit the Olympic cauldron on Friday, was denied a place in the quarter-finals after being ousted 6-1 6-4 by world number 42 Marketa Vondrousova.

This event marked Osaka’s first competitive tennis in two months since her early withdrawal from the French Open at the end of May, citing mental health issues.

The world number two is the latest of the big names to fall at the Tokyo Games, with top seed Ash Barty and third seed Aryna Sabalenka also suffering early exits.

"Of course, it's one of the biggest wins of my career," Vondrousova said. "Naomi is a great player, so I knew it would be a tough match. 

“I'm very happy with my play. I played amazingly in the first set, and then the second set was really tough. I'm just happy to be through."

ARGENTINA RECOVER TO SEE OFF SPRINGBOKS

Argentina recovered from a dreadful start to beat South Africa and book their place in the rugby seven semi-finals.

Trailing 7-0 after just under two minutes, the Pumas were then reduced to six men when Gaston Revol - who was reduced to tears - was shown a straight red card.

Nevertheless, they demonstrated tremendous resilience and character before eventually running out 19-14 winners.

Argentina will play Fiji in the last four after the reigning Olympic champions swept Australia aside 19-0.

Great Britain stormed back from 21-0 down to beat the USA, scoring four tries to secure a dramatic 26-21 victory.

Team GB will play New Zealand, who eased to a 21-10 success over Canada.

Naomi Osaka was never preordained to win gold at the Tokyo Olympics but it had felt that way until she ran into Marketa Vondrousova.

The surprising 6-1 6-4 loss that a lacklustre Osaka suffered on Tuesday could be explained away by the fact the 23-year-old had not played any competitive tennis since pulling out of the French Open at the end of May.

All the same, it was a major upset as world number 42 Vondrousova took out the highest remaining seed in the draw – the Japanese star who lit the Olympic cauldron on Friday.

Osaka's exit, after previous shock defeats for top seed Ash Barty and number three Aryna Sabalenka, has raised the prospect of a shock champion, just as occurred five years ago at the Rio Games when Monica Puig of Puerto Rico caused a sensation.

Now at the quarter-final stage, there is one former grand slam champion left in the field and two finalists at that level, but it really looks like anyone's title.

VONDROUSOVA SENSES AN OPPORTUNITY

It was remarkably straightforward for Vondrousova at Ariake Tennis Park, as she cruised through the opening set and soon reeled in Osaka's early break in the second.

Osaka saved two match points when serving to stay in the contest, but not a third, planting a backhand wide.

Considering Vondrousova reached the French Open final two years ago, in front of packed grandstands rather than the empty seats in Tokyo, it was no surprise she hesitated when asked whether this win over Osaka was the biggest of her career. It probably doesn't have that cachet, good a win though it was.

"Of course it's one of the biggest," Vondrousova said.

"Naomi is a great player, she has so many grand slams, so I knew it would be a tough match. But I'm just very happy with my play. I played amazingly in the first set, and then the second set was really tough. I'm just happy to be through.

"I think she was struggling a bit with my serving. Also, I use drop-shots very well. I'm just very happy with my game today."

She faces Spain Paula Badosa next and said: "It's very open now. I think every girl is playing really well. Now it's the quarter-final, so we'll see."

HAS SVITOLINA'S TIME ARRIVED?

A fixture in the top 10 over recent seasons, Svitolina has been unable to transfer her regular tour form onto the major stage on a consistent basis.

Maybe the Olympics will be a platform towards success on that stage, with Svitolina now the highest seed remaining in the draw, at number four. The Ukrainian is also on a high on the personal front, having married French tennis star Gael Monfils shortly before heading to Tokyo.

Two semi-finals, at Wimbledon and the US Open in 2019, have been her deepest runs in the majors, and this season has been one of diminishing returns, with a fourth-round run in Australia followed by a third-round Roland Garros exit and a round-two loss at Wimbledon.

Svitolina beat Maria Sakkari of Greece 5-7 6-3 6-4 on Tuesday, setting up a quarter-final against Italian Camila Giorgi who won 6-4 6-2 against Wimbledon runner-up Karolina Pliskova.

"I don't think I'm a favourite because there are lots of good players here and everyone is quite equal," Svitolina said.

A MUG SHOT?

Should Spain's Garbine Muguruza be considered the favourite from this point? With French Open and Wimbledon titles in her trophy room, Muguruza has shown she has what it takes to triumph on a big stage, and a clinical 6-4 6-1 win over Belgian Alison Van Uytvanck on Tuesday was just the job.

She goes on to face Elena Rybakina of Kazakhstan, who edged past Croatian Donna Vekic.

Belinda Bencic of Switzerland caused a surprise by ousting the in-form reigning French Open champion Barbora Krejcikova, springing a 1-6 6-2 6-3 win that means there will be no repeat of the Roland Garros final in the quarter-finals.

That had been on the cards, but Bencic will be the player who takes on Anastasia Pavlyuchenkova for a place in the final four.

Pavlyuchenkova scored an impressive 6-1 6-3 victory over Sara Sorribes Tormo of Spain, the player who knocked out Barty in round one.

Russian Olympic Committee's Pavyluchenkova is looking to harness the form that took her to a maiden slam final, describing her Paris run as "a great experience to have".

"But every week is a new week and this is a new event," said the 30-year-old. "The Olympic Games is a very special event. It's different. It's nothing like the others."

Naomi Osaka saw her Tokyo 2020 gold medal hopes go up in smoke after a painful defeat and admitted: "This one sucks more than the others."

The world number two had seen top-ranked Ash Barty bounced out in the first round, and the face of Japan's Games looked primed for a run deep into the tournament.

But the prospects of home glory in women's tennis were dashed in round three when Osaka crumbled 6-1 6-4 to Marketa Vondrousova of the Czech Republic.

Osaka, who lit the Olympic cauldron in Friday's opening ceremony, was left scrambling for answers as to why she underperformed.

"How disappointed am I? I mean, I'm disappointed in every loss, but I feel like this one sucks more than the others," she said.

"I definitely feel like there was a lot of pressure for this. I think it's maybe because I haven't played in the Olympics before and for the first year [it] was a bit much."

Asked what went wrong against the world number 42, Osaka said: "Everything – if you watch the match then you would probably see. I feel like there's a lot of things that I counted on that I couldn't rely on today."

There were certainly mitigating circumstances that the 23-year-old might have pointed to, given she had not played since the French Open before heading into the Olympics.

Osaka pulled out of Roland Garros after winning through her first-round match, citing anxiety and pointing to episodes of depression as she explained why she refused to take part in news conferences during the tournament.

Her declarations in Paris came after the four grand slam tournaments warned she could be thrown out of their events if she persistently refused to talk to the media.

Already a four-time grand slam winner, Osaka has found plenty of public support and there was criticism of the tennis authorities for their stance.

To many in Japan, she can do little wrong, although she could also do little right against Vondrousova. Osaka had 32 unforced errors to just 10 from Vondrousova, who also hit more winners.

After saving two match points, Osaka swung a backhand wide on a third to seal her exit.

Despite her disappointment, Osaka felt she had given a reasonable account following a recent absence from the tour, which saw her miss Wimbledon.

But the Games called for more than that, and it was a deflated Osaka who spoke afterwards, explaining how the pressure on her shoulders proved overbearing.

"I've taken long breaks before and I've managed to do well," she said. "I'm not saying that I did bad right now, but I do know that my expectations were a lot higher.

"I feel like my attitude wasn't that great because I don't really know how to cope with that pressure, so that's the best that I could have done in this situation."

Naomi Osaka saw her Olympic gold medal dream shattered by a third-round defeat to Marketa Vondrousova at Tokyo 2020 on Tuesday.

Osaka lit the Olympic cauldron on Friday and was widely hailed as the 'face of the Games', with enormous expectation that she would go on to triumph for hosts Japan.

The early exit of world number one Ash Barty seemed to help her case, but Osaka lost 6-1 6-4 to her Czech opponent in an hour and eight minutes.

Osaka played a dismal opening set but then looked to have raised her game a notch in the second, establishing an early break.

However, that did not herald a full-blown fightback as former French Open runner-up Vondrousova soon got back on level terms and forced Osaka to serve to stay in the contest.

From 15-40, Osaka saved two match points, but Vondrousova soon had a third opportunity and her spirited defence won out.

Osaka flung a backhand wide this time and Vondrousova had her prized scalp, securing a place in the quarter-finals at the expense of the world number two.

It was an untidy performance from Osaka who made 32 unforced errors to just 10 from Vondrousova.

This was Osaka's first tournament since pulling out of the French Open at the end of May, in the wake of a first-round win. She cited depression and anxiety issues in Paris after announcing she would not take part in news conferences during the tournament.

Japanese superstar Naomi Osaka crashed out of the Tokyo Olympics tennis with a 6-1 6-4 defeat to Czech world number 42 Marketa Vondrousova.

Osaka, who lit the flame at Friday's opening ceremony, had won her opening two matches but bowed out in straight sets, with Vondrousova reaching the quarter-finals.

In the first set, Vondrousova dominated on her first serve and broke three times, before the Japanese hit back with an early break in the second. But the Czech fought back to win, with Osaka finishing with 32 unforced errors to just 10 by her opponent.

"Of course it's one of the biggest wins of my career," Vondrousova said. "Naomi is a great player, she has so many grand slams, so I knew it would be a tough match. I'm very happy with my play. I played amazingly in the first set, and then the second set was really tough. I'm just happy to be through."

World number two Osaka joins top seed and Wimbledon champion Ash Barty in being eliminated early at the Tokyo Games.

In the men's singles second round, fourth-ranked Greek Stefanos Tsitsipas eased past American Francis Tiafoe 6-3 6-4, avenging a shock Wimbledon defeat.

DUFFY DELIGHT

Flora Duffy won Bermuda's first-ever Olympic gold medal with victory in the women's triathlon on Tuesday at Odaiba Marine Park.

The four-time Olympian failed to finish in Beijing, came 45th in London and improved to eighth in Rio de Janeiro.

Duffy took the Tokyo title in a time of one hour, 55 minutes and 36 seconds, finishing more than a minute ahead of Britain's Georgia Taylor-Brown who took silver, with USA's Katie Zaferes claiming bronze.

“It's always been my dream to race at the Olympics and be a professional athlete with the goal of being an Olympic champion," Duffy said.

"That's not the easiest thing to do regardless of where you're from. Bermuda is a small country, but it's really passionate about its sport.

“I'm so grateful that I could achieve a personal dream here of winning an Olympic medal, but this is bigger than me, this is going to inspire the youth of Bermuda and everyone back home that competing on the world stage from a small island is really possible."

The 33-year-old broke clear in a group of seven early in the bike stage, before dominating the 10km run.

Bermuda, which has a population of just over 70,000, had only claimed one medal previously in Olympic history, a bronze in 1976.

MCKEOWN BREAKS OLYMPIC RECORD

Australia secured a second gold medal in the pool as Kaylee McKeown broke the Olympic record in the women's 100m backstroke.

McKeown won in 57.47, finishing ahead of Canada's Kylie Masse by 0.25 seconds, with USA's Regan Smith taking bronze. Masse had led at the turn.

In the men's 100m backstroke, Russian Olympic Committee claimed a one-two finish as Evgeny Rylov edged out countryman Kliment Kolesnikov, who holds the 50m world record. Ryan Murphy, who is the world record holder across 100m, claimed bronze.

Great Britain's Tom Dean won the men's 200m freestyle by 0.04, marginally ahead of compatriot Duncan Scott, with Brazil's Fernando Scheffer coming in third. The result meant two British male swimmers stood on the same Olympic podium for the first time since 1908.

World record holder Lilly King finished third as US teenager Lydia Jacoby triumphed in the women's 50m breaststroke. South Africa's Tatjana Schoenmaker claimed silver.

CHINESE PAIR ON TARGET

China claimed another gold medal in the final of the 10m air pistol mixed team at the Asaka Shooting Range.

China's Ranxin Jiang and Wei Pang won 16-14 over Russian Olympic Committee pair Vitalina Batsarashkina and Artem Chernousov.

Ukraine duo Olena Kostevych and Oleh Omelchuk won the bronze by beating Serbia.

The 10m air rifle mixed team bronze and gold medal matches were taking place later on Tuesday.

AUSSIES SINGING IN MEN'S HOCKEY

World number two side Australia knocked off reigning Olympic gold medallists Argentina 5-2 in the men's hockey group stage.

Australia claimed their third consecutive victory and top Group A, this time being aided by two goals from Blake Govers.

The Kookaburras have only won one Olympic gold despite often being a dominant side in men's hockey and are one of the favourites to triumph in Tokyo.

Japan and New Zealand, who both previously lost to Australia, drew 2-2 in the other Group A game.

In Group B, world number four India won 3-0 over Spain, while fifth-ranked Germany beat Great Britain 5-1.

Naomi Osaka saw her Olympic gold medal dream shattered by a third-round defeat to Marketa Vondrousova at Tokyo 2020 on Tuesday.

Osaka lit the Olympic cauldron on Friday and was widely hailed as the 'face of the Games', with enormous expectation that she would go on to triumph for hosts Japan.

The early exit of world number one Ash Barty seemed to help her case, but Osaka lost 6-1 6-4 to her Czech opponent in an hour and eight minutes.

The Tokyo Olympics are now in full swing and there are another 22 gold medal events to come on an action-packed Tuesday at the Games.

Plenty of focus will be on the Tokyo Aquatics Centre once again, where four medals are on the line, while the women's triathlon will also take centre stage.

Simone Biles, Naomi Osaka and Katie Ledecky are just some of the superstar names that will be in action on the fourth full day of the 2020 Games.

Stats Perform picks out of some of the standout action to look out for.

CAN BILES PUT BLUNDERS BEHIND HER?

Biles struggled to find top gear in her Games entrance on Sunday, albeit making it through to each of her finals, and there is no room for any slip-ups in the women's team final.

The Russian Olympic Committee finished above the United States at a major event for the first time since 2010 in qualifying, setting up an intriguing battle in the final.

The pressure is on Suni Lee, Jordan Chiles, Grace McCallum and indeed Biles, the latter of whom is aiming to add to the four golds won in Rio five years ago.

USA-JAPAN MEET IN SOFTBALL FINAL

Team USA's women's softball team recovered from behind to beat Japan 2-1 in their final round-robin game and finish top of the standings.

Japan finished second and the two sides are therefore set to face off in a huge gold medal match at Yokohama Baseball Stadium.

Mexico and Canada meet in the bronze medal contest earlier on Tuesday in a tasty warm-up match for the main event.

LEDECKY AND TITMUS RESUME RIVALRY

After winning four golds in Rio five years ago, Ledecky had the chance to add four more to her collection in Tokyo.

She fell short in the first of those events, however, with Australia's Ariarne Titmus taking gold in Monday's gripping 400m freestyle final.

While a medal is not on the line on Tuesday, Ledecky will be eager to lay down a faster time than her rival in the 200m freestyle heats ahead of Wednesday's showpiece.

OSAKA GOES AGAIN

Face of the Games Okaka followed up lighting the Olympic cauldron on Friday with victories over Zheng Saisai and Viktorija Golubic in her first two matches in the tournament.

The four-time grand slam winner has a quick turnaround in matches as world number 41 Marketa Vondrousova awaits in the third round on Tuesday.

Fellow home favourite Kei Nishikori is also in action in the men's event, with Marcos Giron standing between him and the last 16.

WOMEN'S TRIATHLON TOUGH TO CALL

There was drama before the men's triathlon had even officially got underway on Monday, with an inflatable boat carrying photographers causing a false start.

Norway's Kristian Blummenfelt won the competition and now it is over to the women, with 54 athletes in contention to claim gold.

The field is wide open this time around, though the likes of Katie Zaferes and Georgia Taylor-Brown, of Team USA and Great Britain respectively, will have their eyes on the top prize.

Naomi Osaka is taking things "one notch at a time" at Tokyo 2020 after another convincing performance in round two on Monday.

With Ash Barty having suffered a shock exit a day prior, Osaka is now the favourite for glory on home court and with Aryna Sabalenka and Iga Swiatek among the round-two casualties that status is sure to only be enhanced.

There was better news for Elina Svitolina and Karolina Pliskova at the Ariake Tennis Park, though, in a women's draw stacked with top-tier talent.

OSAKA NOT GETTING AHEAD OF HERSELF

Back after a self-imposed two-month hiatus, defending US and Australian champion Osaka has not missed a beat and was too good for Viktorija Golubic in a 6-3 6-2 victory.

Osaka won 24 of 26 service points in the first set and 37 of 45 in the second, facing break point only once in a one-sided affair.

"It would mean a lot to win gold here, but I know it's a process," she said. "I know these are the best players in the world and honestly I haven't played in a while, so I'm trying to take it one notch at a time.

"All in all, I'm just really happy to be here. I haven't been in Tokyo for a couple of years."

Svitolina was not as comfortable with the fourth seed rebounding from losing the opening set to defeat Ajla Tomljanovic 4-6 6-3 6-4. Maria Sakkari (14) awaits in the next round.

Carla Suarez Navarro earned her first win since recovering from cancer in round one and battled valiantly against Karolina Pliskova (5) before eventually losing in three sets.

Garbine Muguruza (7), Barbora Krejcikova (8) and Belinda Bencic all coasted through in straight sets, as did Anastasia Pavlyuchenkova (13) and Elena Rybakina (15).

TEARS FOR IGA 

Swiatek, whose father was an Olympic rower, would have had strong designs on a deep run at the Games but was beaten 6-3 7-6 (7-4) by Paula Badosa.

The Pole was left in tears after the defeat, and was still sobbing at her chair several minutes after the end of the match.

Sabalenka also bit the dust, going down in three sets to Donna Vekic, while Petra Kvitova lost the deciding set of her tie with Alison Van Uytvanck 6-0 to bow out with a whimper.

Norway's Kristian Blummenfelt said he never had a doubt he would win the triathlon, and his confidence never wavered as he pulled away late to take the gold. 

The top contenders spent much of Monday's race biding their time, with all the favourites in the mix following the swim and bike legs, but Blummenfelt drove the pace on the final leg. 

When the lead group winnowed down to himself, Great Britain's Alex Yee and Hayden Wilde of New Zealand, Blummenfelt urged the 23-year-olds to keep the hammer down – then ran away from them in the end. 

One last kick over the final kilometre put Blummenfelt atop the podium, with Yee taking silver and Wilde bronze. 

"We were like 10 guys in the running lead and when he picked up the pace I saw that we were down to four and I tried to get [Yee] motivated to keep the pace," Blummenfelt told reporters.

"I said, 'Guys, we have a medal now, keep the gas on,' and I think that for Alex and Hayden this is a great moment to get an Olympic medal, too."

Yee's compatriot Jonathan Brownlee, who won silver in the event in Rio and bronze in London as his brother Alistair took gold in both races, finished fifth on Monday.

"I told myself last night that all I can do is try my hardest and before that, prepare," Brownlee said. "I did everything I could, I got ready for the heat, I trained as hard as I could, had a great team around me and that's all you can ask.

"I think I've been very, very fortunate in my two Olympic Games, I've had two medals. It's hard to perform and I've performed well in three." 

'NERVOUS' OSAKA KEEPS ROLLING

Playing for the second consecutive day, second-seed Naomi Osaka showed no signs of fatigue as she cruised to a 6-3 6-2 second-round victory over Switzerland's Viktorija Golubic on Sunday. 

Japan's big hope Osaka had to play back-to-back after having her schedule altered following the honour of lighting the Olympic cauldron Friday, and the other top women in action looked just as strong after a day off Sunday. 

"Honestly, I feel like I was a bit more nervous before the match," Osaka told reporters. "I felt a lot of butterflies, but I think as I started playing and feeling more comfortable, I knew that no matter what it would be a great match."

After pulling out of the French Open before the second round and skipping Wimbledon, the four-time grand slam winner has not had much match time over the last two months, but her goal in Tokyo remains the same. 

“It would mean a lot to win gold here, but I know it's a process," she said. "I know these are the best players in the world, and honestly I haven't played in a while, so I'm trying to take it one notch at a time.

"All in all, I'm just really happy to be here. I haven't been in Tokyo for a couple of years."

In other early matches, seventh-seeded Garbine Muguruza of Spain rolled past China's Wang Qiang 6-3 6-0, while eighth seed Barbora Krejcikova had a tougher time with Canada's Leylah Annie Fernandez before moving on 6-2 6-4 and 11th seed Anastasia Pavlyuchenkova defeated Anna-Lena Friedsam 6-1 6-1. 

MACNEIL EARNS CANADA'S FIRST GOLD

It took Margaret MacNeil a few moments to realise she had won Canada's first gold medal of the Tokyo Games.

The 21-year-old usually wears contact lenses but does not put them on when she is in the pool, so she had to focus to see her name atop the scoreboard after the 100m butterfly at the Tokyo Aquatics Centre. 

"I like to check the scoreboard pretty quickly, but it's hard just because I don't have contacts," she said. "It does take me a minute to read the scoreboard, so I was just trying to squint and see where I came."

Her vision problems may have been a benefit during the race, which saw her edge China's Zhang Yufei by 0.05 from lane seven. 

"I could hardly see anyone on the far side of the pool, which I think helped me a lot, because I was able to just focus on my own race," MacNeil said. "I just put my head down and tried to get to the wall as fast as possible. I'm really glad it all came together."

While MacNeil took the first gold medal in the pool Monday, her win was overshadowed by later events. 

Great Britain's Adam Peaty defended his Olympic title in the 100m breaststroke, while Ariarne Titmus of Australia dethroned the reigning champion Katie Ledecky in the 400m freestyle. 

In the final medal event of the day, Caeleb Dressel – Michael Phelps' heir apparent – and the USA won the 4x100m freestyle relay by 1.14 seconds over Italy. 

UPSETS ABOUND IN FENCING

Three of the top six women in the world were eliminated early in the women's sabre competition Monday. 

Top-ranked Olga Kharlan of Ukraine, twice a bronze medallist, fell to Yang Hengyu of China 15-12 in the round of 32 to end her hopes of a third straight medal. 

Fourth-ranked Shao Yaqi of China and world number six Anne-Elizabeth Stone of the USA went out in the same round. 

Sofia Velikaya of Russia, who took silver in Rio, remains alive heading into the quarter-finals later Monday along with 2016 fourth-place finisher Manon Brunet of France. 

REIGNING CHAMPIONS FIJI OPEN RUGBY SEVENS PLAY

Reigning gold medallists Fiji rallied in the second half to defeat Japan 24-19 in a rematch of the Rio 2016 semi-finals. 

Fiji trailed 19-12 but fought back through a pair of tries and a conversion from substitute Waisea Nacuqu in the final four minutes.

The team they beat for gold five years ago, Great Britain, opened play with a flourish, thrashing Canada 24-0, while New Zealand crushed South Korea 50-5. 

Fourth-place finishers in 2016, South Africa defeated Ireland 33-14 while Argentina beat Australia 29-19 and the United States edged Kenya 19-14. 

Ash Barty says she will keep fighting for an Olympic gold medal despite her shock opening-round defeat by Sara Sorribes Tormo in Tokyo.

The world number one fell at the first hurdle at Arianke Tennis Park, going down 6-4 6-3 against her Spanish opponent.

There were no such problems for Naomi Osaka; the home favourite overcame China's Zheng Saisai in straight sets.

BARTY TO KEEP FIGHTING FOR GOLD MEDAL

Crowned Wimbledon champion this month, Barty was unable to build on that momentum; amassing a whopping 55 errors.

World number 48 Sorribes Tormo took full advantage to set up a second-round showdown with France's Fiona Ferro.

Naomi Osaka is feeling "a little bit refreshed and happy again" after returning to tennis with a convincing 6-1 6-4 triumph over Zheng Saisai in her Tokyo 2020 opener.

The four-time grand slam winner has not featured since the first round of the French Open two months ago where she abandoned her campaign following a warning she risked expulsion over her refusal to take part in news conferences during the tournament.

Osaka, who is the reigning US and Australian Open champion, then decided to skip Wimbledon after opening up on her battles with anxiety and depression.

The 23-year-old was granted the honour of lighting the flame for Tokyo 2020 on Friday and two days later made a successful return at the Ariake Tennis Park, where she represents one of Japan's greatest medal hopes for the Games.

"I feel like, more than anything, I'm just focused on playing tennis. This, playing the Olympics, has been a dream of mine since I was a kid, so I feel like the break I took was very needed," she said.

"But I feel definitely a little bit refreshed and happy again.

"I felt really nervous being in Japan and playing here for the first time in maybe two years, and for it to be my first Olympics. 

"It was definitely really nerve-wracking. But I am glad I was able to win, she is a very tough opponent.

"It's been a while since I played but I feel, more than anything, just happy to be out here. We are playing in a pandemic, and it is really tough for everyone."

Asked how she felt to be talking to the press again, she said: "For me, honestly I don't feel that weird about it.

"It might feel weird to you guys, but I don't know. I'm happy that I guess you guys are asking me questions but more than anything I was just focused on playing tennis and I guess I feel a little bit out of my body right now."

Osaka then revealed that her starring role in Friday's opening ceremony came about in March.

"I was super honoured," she said. That’s a position you dream about and not anyone can do it so when they asked me if I wanted to I was very surprised but very honoured and I'm just happy to be here and happy to play, especially in Tokyo."

The playing conditions have been a quite literal hot topic over the first two days, with the sweltering heats causing issues for players.

Daniil Medvedev and Novak Djokovic were among those to speak out about the decision not to play matches later in the day Tokyo, where temperatures have regularly been above 30 degrees.

Osaka, though, has no such issues, adding: "It feels fine for me. I have played a couple of tournaments here, of course they resurfaced it since I was last here, but I love being here, and I actually really like the weather."

Naomi Osaka lighting the Olympic cauldron will have helped increase the exposure for the sport of tennis around the world, according to Novak Djokovic.

Osaka was given the honour of carrying the torch on the short final leg at the Japan National Stadium before walking the steps to light the flame and end the opening ceremony.

The four-time grand slam champion is the face of the Tokyo Games in her home country, creating extra pressure on her shoulders as she bids to strike gold.

Djokovic appreciates the absences of legendary names Roger Federer and Rafael Nadal is a blow, but he believes Osaka's presence is crucial for tennis in the battle for media coverage at the Games.

"It cannot be better for our sport, you are representing yourself, your country but also your sport in the Olympic Games, you're trying to get the hype and the attention towards our sport as much as you possibly can, so we're all contributing to that in the Olympic Village," Djokovic said when asked about Osaka's role in Friday's ceremony.

"There's a lot of attention towards the tennis players which is great, from the other athletes which is very nice to see, very nice to experience.

"Obviously you don't have Roger or Rafa. They are big stars and legends of our sport, but still there's quite a lot of great athletes, top players. Naomi is a home favourite and a lot of eyes are on her.

"Being at home playing is a lot of pressure, but it's great for our sport just in general to see that there's a lot of attention towards it."

Djokovic was speaking after overcoming Hugo Dellien with ease in his opening outing in the men's singles tournament, the Serbian triumphing 6-2 6-2 in just over an hour.

The quick win allowed the recently crowned Wimbledon champion to avoid staying out for too long in the Tokyo heat, an issue that led to Daniil Medvedev calling for matches to be pushed back to later in the day, allowing players to compete during the evenings when the temperatures have dropped.

"I agree with him 100 per cent," Djokovic said of Medvedev's suggestion. "I actually asked as well.

"My team captain, Viktor Troicki, was speaking to the referee a couple of times. To be honest, I don't understand why they don't start matches at say 3pm.

"I've heard for tennis there is some kind of curfew they have to finish at midnight, but if that's the case, I've just finished the last match and it's not even 5pm, we still have seven hours to play. 

"They have lights on all the courts, they're going to make life much easier for all of us tennis players, I just don't understand why they don't move it. 

"It's actually for the television broadcasters even better, because the later you play, the better it is for the United States and the time zones in Europe.

"I don't know, maybe the ITF (International Tennis Federation) can give you a better answer to why they chose to be played in the middle of the day. I doubt they will change the decision, but we're hoping that they will."

Naomi Osaka will make her playing entry to the Olympic Games a day later than expected after her first-round tennis match was put back to Sunday.

Japan's big hope for gold will play China's Zheng Saisai in her opener at the Ariake Tennis Park.

The match was billed to be first on the centre court at 11:00 local time on Saturday, only for Games organisers to announce it has been moved back by a day.

The move came amid mounting expectation that Osaka would have a prominent role to play in Friday's opening ceremony, meaning she would have little time to rest between taking part in that event and playing Zheng.

Osaka abandoned her French Open campaign after one match, having been warned she risked expulsion for refusing to take part in news conferences during the tournament.

The reigning US Open and Australian Open champion, who has spoken of struggling with anxiety and depression, then elected to skip Wimbledon.

Ash Barty and home favourite Naomi Osaka start their respective quests for Olympic gold against Sara Sorribes Tormo and Zheng Saisai, while Novak Djokovic opens against Hugo Dellien.

In a stacked women's draw, world number one and Wimbledon champion Barty has a tough opening assignment and could face French Open finalist Anastasia Pavlyuchenkova, the 13th seed, as early as round three.

Spectators may not be in attendance at Tokyo venues for the Olympics but Japanese fans will be rooting for Osaka, who returns to action after a two-month hiatus with the four-time grand slam winner having spoken openly about mental health and anxiety issues.

Viktorija Golubic or Maria Camila Osorio Serrano would await Osaka if she can get through round one, but a dream final with Barty is no shoo-in given 15 of the world's top 20 on the WTA Tour are in action including each of the nine leading the race for the 2021 WTA Finals.

Aryna Sabalenka (3), Elina Svitolina (4), Wimbledon runner-up Karolina Pliskova (5), Iga Swiatek (6) and Garbine Muguruza are all featuring in Tokyo.

The men's side has been hit by a spate of withdrawals, with Rafael Nadal, Roger Federer and Dominic Thiem among those not playing in the Japanese capital.

The main talking point surrounds whether the all-conquering Djokovic can continue his march towards a calendar Golden Slam – a sweep of all four majors and an Olympic gold in the same year.

Any notion of a free ride for the Serbian is wide of the mark, though. His side of the draw could see him come up against Andrey Rublev (5), Alexander Zverev (4) and Hubert Hurkacz (7), while Stefano Tsitsipas (3) – beaten by Djokovic in the French Open final – and Daniil Medvedev (2) are among the potential final opponents.

Andy Murray, gold medal winner in 2012 and 2016, faces Canada's Felix Auger-Aliassime in a tricky first-round match.