Naomi Osaka is through to the third round of the Miami Open after beating former world number one Angelique Kerber in straight sets.

Osaka won the first three games of the match to jump out to an early lead, securing the set with a double-break before breaking early in the second to cruise to a 6-2 6-3 win.

The story of the match was Osaka's ease in winning points against Kerber's serve, winning 41 per cent (15/37) of Kerber's successful first serves, while the German could only win 11 per cent (3/27) in the same category.

Britain's top-ranked woman Emma Raducanu suffered another early exit, on the wrong end of Katerina Siniakova's comeback 3-6 6-4 7-5 win.

World number one Daniil Medvedev hopes that Russian and Belarusian tennis players will be allowed to continue competing but acknowledges there remains a chance of further restrictions.

The governing bodies of tennis (the International Tennis Federation, ATP, WTA, and the four Grand Slam events) recently announced that Russian and Belarusian players can no longer compete under the flags of their respective countries.

Russia launched a full-scale military assault on Ukraine last month, a move that received the backing of Belarus, leading the ITF to revoke Russian and Belarussian membership and suspend the countries' teams.

That decision followed in the footsteps of rulings relating to Russian teams or competitors in various sports, including football and athletics.

Medvedev, who recently talked of his wish to "promote peace", said he hopes to continue to play, ahead of the first Masters event of the year in Indian Wells.

"It's always tough to talk on this subject because I want to play tennis, [to] play in different countries," the 26-year-old said.

"I want to promote my sport.

"I want to promote what I'm doing in my country for sure, and right now the situation is that that is the only way I can play [without representing Russia]."

Two of the top three seeds crashed out of the WTA Qatar Open in the round of 16 as Barbora Krejcikova and Paula Badosa both lost, though top seed Aryna Sabalenka is through to the quarter-finals, along with Coco Gauff.

Sabalenka eased past Jil Teichmann 6-2 6-1 in Doha, winning an impressive 70 per cent of her second serves as she rarely gave her Swiss opponent any hope in a match that lasted just over an hour.

The Belarusian will now play Iga Swiatek in the last eight after the seventh seed beat Daria Kasatkina 6-3 6-0.

Number two seed Krejcikova was eliminated by the winner in Dubai last week, Jelena Ostapenko, 6-3 6-2. The Czech struggled to get going and ended the match with seven double faults to her name.

World number four Badosa fared no better as she also lost in straight sets to Gauff 6-2 6-3, with the 17-year-old winning a dominant 77.1 per cent of points on her first serve.

Badosa is the joint-highest ranked player that Gauff has defeated, along with Naomi Osaka, who was also ranked fourth in the world when she lost to the teenager at the 2020 Australian Open.

Gauff will now face Maria Sakkari after the Greek defeated another American, Jessica Pegula.

Ostapenko will go up against reigning WTA Finals champion Garbine Muguruza who convincingly defeated Madison Brengle 6-0 6-2.

Number four seed and St Petersburg champion Anett Kontaveit is through after a topsy-turvy clash with Elise Mertens 6-3 0-6 6-2 and will come up against Tunisia's Ons Jabeur.

Defending champion Petra Kvitova and former world number one Victoria Azarenka were both forced to withdraw from the WTA Qatar Ladies Open through injury on a day where the top seeds all cruised through in Doha.

Kvitova – who won the 2018 and 2021 editions of the tournament, beating Garbine Muguruza in the final on both occasions – was left unable to continue during her clash with Elise Mertens, later tweeting that an injury to her left wrist had flared up during the second set.

Her conqueror Mertens will face fourth seed and WTA St Petersburg champion Anett Kontaveit in the round of 16 after the Estonian's win over Ana Konjuh on Monday.

Meanwhile, Azarenka joined Kvitova in announcing her withdrawal through injury, suffering pain in her left hip ahead of her scheduled clash with American Madison Brengle.

The tournament's top seeds had more luck on a day of few surprises. World number two Aryna Sabalenka breezed to a 6-2 6-2 victory over France's Alize Cornet, with the Belarusian the favourite for the first WTA 1000 event of the year as world number one Ashleigh Barty is missing through injury.

Elsewhere, world number three Barbora Krejcikova made light work of Poland's Magda Linette, winning 6-1 6-3, and will face former French Open champion Jelena Ostapenko in the round of 16, having eliminated the Latvian from last month's Australian Open.

Paula Badosa also recorded a straight-sets victory, seeing off Clara Tauson 6-1 6-2 to reach the last 16, where she will face 17-year-old American Cori Gauff, who defeated France's Caroline Garcia 6-2 7-6 (7-3).

There were also three-set wins for top-10 players Iga Swiatek and Ons Jabeur, with Swiatek beating Viktorija Golubic 6-2 3-6 6-2, and Jabeur overcoming Aliaksandra Sasnovich 1-6 7-5 6-3.

In the final match of the day, world number six Maria Sakkari downed American Ann Li 6-3 6-3.

Defending champion Garbine Muguruza, 2021 finalist Barbora Krejcikova and top seed Aryna Sabalenka were all eliminated from the Dubai Tennis Championships on Wednesday.

A day of upsets left Ons Jabeur, the eighth seed, as the top remaining player in the draw.

Some big names helped deliver the shocks, though, with world number two Sabalenka usurped by two-time Wimbledon champion and 2013 Dubai winner Petra Kvitova in straight sets.

Muguruza did not look like being one of the scalps as her title defence continued against Veronika Kudermetova.

But after taking the first set, the reigning WTA Tour Finals champion went down 3-6 6-4 6-4.

French Open champion Krejcikova, beaten by Muguruza in the final last year, also exited the tournament at the hands of Dayana Yastremska 6-3 7-6 (7-3).

Iga Swiatek let a set lead slip to Jelena Ostapenko, while two-time Dubai champion Elina Svitolina collapsed to lucky loser Jil Teichmann 7-6 (7-0) 6-2.

Jabeur, a winner against Jessica Pegula, was the only seed to win in a ruthless round of 16.

However, her reward in a still stacked quarter-final draw is a meeting with Simona Halep, another who has twice won in Dubai.

Top seed Aryna Sabalenka and defending champion Garbine Muguruza came through their first-round matches unscathed at the Dubai Tennis Championships on Tuesday.

Belarusian Sabalenka made light work of 19-year-old Marta Kostyuk, sealing a 6-4 6-1 win in one hour and 15 minutes.

Standing in her way of a third consecutive quarter-final in Dubai is Petra Kvitova, who beat Camila Giorgi on Monday.

Last year's champion and fourth seed Muguruza began her title defence with a 7-6 (7-5) 2-6 6-2 win over Czech qualifier Katerina Siniakova in two hours and 24 minutes.

Spaniard Muguruza will face Veronika Kudermetova in the second round after the Russian beat former world number one Victoria Azarenka in straight sets earlier on Tuesday.

There were also wins for eighth seed Ons Jabeur and 10th seed Elina Svitolina against Vera Zvonareva and Mayar Sherif respectively.

Elsewhere, there was a shock as qualifier Elena-Gabriela Ruse dumped out third seed Paula Badosa 6-3 5-7 6-4.

Ninth seed Danielle Collins is also out after the American retired due to dizziness in the second set against Marketa Vondrousova.

Sofia Kenin failed to put up a fight as she went down 6-1 6-2 to Jelena Ostapenko.

Kaia Kanepi surprised even herself by holding her nerve to eliminate second seed Aryna Sabalenka in a final-set tie-break and reach Australian Open quarter-finals for the first time.

The world number 115 edged a topsy-turvy battle 5-7 6-2 7-6 (10-7) on Margaret Court Arena to set up a meeting with Iga Swiatek in the final eight.

With Monday's impressive comeback win, Kanepi has now completed a clean sweep of reaching the quarter-finals of all four majors, making her the 15th active player to do so.

But after squandering four match points in the 10th game of the deciding set, Kanepi admits she struggled to keep her nerves in check when the match went the distance.

"I thought I was going to lose it after the match points I had on my serve," said the 36-year-old, who finished with 30 winners and 30 unforced errors.

"It was really difficult to come back. I don't know how I managed to do it.

"I was really tight. My hand was shaking when I started serving. I didn't make any first serves in, and that added to the pressure.
 
"It was quite crazy. I think I would be more happy if I won after two, three match points. It was really close that I lost the match. I feel a bit exhausted right now.

"The Australian Open was the only quarter-final grand slam I was missing. Given my age, I didn't actually believe I was going to do it. I'm really happy."

After sealing a 14th career victory over a top-10 opponent, with her second win in a row against Sabalenka, Kanepi is now relishing Wednesday's battle with Swiatek.

That will pit the youngest and oldest remaining players left in the draw against each other, with 20-year-old Swiatek having earlier defeated Sorana Cirstea in three sets.

"I haven't watched her, I never played her, and I don't know how her ball feels, so we'll see when I play her," Kanepi said of her next opponent. "What I expect is to play good."

Kanepi is one of six Australian Open quarter-final debutants remaining, with top seed Ash Barty and Madison Keys the only two to have previously reached this stage.

The tennis season has begun with Rafael Nadal, Ash Barty, Paula Badosa and Thanasi Kokkinakis among the champions at small-scale events in Australia.

Yet there has been one dominant story in the sport and little else has had a look-in in the lead-up to the Australian Open.

Now that Novak Djokovic knows his fate, there is the welcome prospect of eyes turning to matters on the tennis court, rather than the Federal Court.

With the action getting under way in Melbourne on Monday, Stats Perform looks at the main protagonists and what the numbers tell us about another high-stakes grand slam.

Djokovic absence blows open men's draw

As defending champion Djokovic heads for home, it is worth a reminder of how he has dominated this tournament.

Nine of his grand slam titles have come in Melbourne, and he has taken the trophy in each of the last three years, helping him cosy up alongside Roger Federer and Rafael Nadal on 20 majors, an all-time record they share. Of the 'Big Three', only Nadal is in the draw this year, with Federer currently on the injured list.

Djokovic has the highest win percentage in the Open Era (since 1969) at the Australian Open, among players with 20 or more wins (91.1 per cent – W82 L8). He was hoping to join Nadal (13 French Opens) and Margaret Court (11 Australian Opens) in the exclusive club of players to reach double figures for singles titles at one slam.

The Serb was also aspiring to become the first man in the Open Era to win four consecutive Australian Opens. It happened once before the tour turned professional, with Roy Emerson winning five in a row from 1963 to 1967. Djokovic has left Melbourne with the title every time that he has made it through to the semi-finals.

So who takes the title now?

Only Bjorn Borg (89.2 per cent) has a higher winning percentage in grand slam matches than Nadal (87.7 per cent) and Djokovic (87.5 per cent) in the Open Era, among players with 100 or more wins. So why not Nadal?

The 35-year-old and Djokovic have carved up 12 of the last 14 grand slam titles, Nadal winning four of those (three French Opens, one US Open). He is battling back from a foot injury lay-off and coronavirus, and might need to get the early rounds out of the way without undue stress to stand a chance at the business end.

The two exceptions in the Nadal-Djokovic sequence of slam dominance have come at the US Open, with Dominic Thiem winning in New York in 2020 and Daniil Medvedev triumphing at Djokovic's expense in last year's Flushing Meadows final. Thiem is not in Australia, but world number two Medvedev is, looking to become the third Russian man to win two slams, after Yevgeny Kafelnikov and Marat Safin.

The last man other than Federer, Nadal and Djokovic to secure back-to-back slam singles title was Andre Agassi (US Open 1999 and Australian Open 2000), but that is Medvedev's objective now, and he has the game to pull it off.

Nadal has reached at least the quarter-final stage in 15 of his last 16 grand slam appearances, winning six of those majors (four French Opens and two US Opens), so he may well be a factor.

Who else is in the frame? Alexander Zverev probably, having reached the quarter-finals in Australia in the last two seasons (SF in 2020 and QF in 2021). He won the Olympic Games and ATP Finals titles last year, so a grand slam is an obvious next step. He might want to keep double faults in check though, having served a tour-high 113 in slams last season.

Stefanos Tsitsipas reached the Australian semi-finals in 2019 and 2021, so throw him into the mix too, and Matteo Berrettini might be a threat. The Italian, a runner-up to Djokovic at Wimbledon in July, served more aces than any other player in grand slams last year (311 aces, 16.4 on average per match).

Others have more modest ambitions

Andy Murray is back at the Australian Open for the first time since 2019, when he lost in the first round against Roberto Bautista Agut in five sets and was more or less given his last rites as a tennis pro after the match, having indicated he was close to retirement.

The five-time Australian Open runner-up last won a match in this tournament in 2017, when he reached round four. A tough opener against Nikoloz Basilashvili awaits.

Spanish 40-year-old Feliciano Lopez will make his 80th appearance in a grand slam and become the second man in the Open Era with 80 or more appearances at the four majors, after Federer (81).

Do not expect an Australian to be men's champion, by the way. The last time an Australian reached the men's singles final was 2005, when Lleyton Hewitt lost against Safin, and the last home champion was Mark Edmondson in 1976.

Barty backed in stacked women's draw

For the first time since 1997, neither Serena nor Venus Williams will take part in the Australian Open. Yet the women's tour is in rude health, even without those great bastions.

Ash Barty is world number one and a standout pick for many, only enhancing her claims after winning an Adelaide International title in the run-up to this fortnight.

But there is staggering depth on the women's side at present, and Barty will face stiff competition.

Incredibly, the last five grand slam finals have featured 10 different women, and teenager Emma Raducanu's against-all-odds US Open triumph in September shows best of all that new stars are emerging.

Yet since 2000, only three non-seeded players have reached the women's singles final at the Australian Open: Serena Williams in 2007, Justine Henin in 2010 and Garbine Muguruza in 2020. 

Barty could become the first Australian to be women's champion since Chris O'Neil in 1978, and the first to reach the final since Wendy Turnbull lost to Hana Mandlikova in 1980.

The Queenslander is the top seed, and the last time the number one failed to reach at least the fourth round at Melbourne Park was in 1979, when Virginia Ruzici lost her opening match. Barty ended a long wait for an Australian winner of the women's title at Wimbledon last year, so why not closer to home as well?

Naomi Osaka is back, so what should we expect?

Truth be told, that's hard to know. Osaka took time out from tennis after the US Open to focus on her mental health and enjoyed hanging out with friends, before deciding she missed tennis enough to go back on tour.

She had three wins at the Melbourne Summer Set tournament recently before withdrawing from a fourth match, saying her body had "got a shock" from the intensity. As defending champion in the season's first major, she has a target on her back and will need to find a way to handle that.

Over the past six seasons, only Osaka has managed to win back-to-back grand slam singles titles among the women, and she has done so twice (US Open 2018 and Australian Open 2019, plus US Open 2020 and Australian Open 2021).

The last player to win back-to-back women's Australian Open singles titles was Victoria Azarenka (2012 and 2013), so it does not happen regularly.

Osaka has an 85 per cent win rate at this tournament: since 2000, only Jennifer Capriati (90 per cent) and Serena Williams (89 per cent) have had a higher win percentage in the main draw.

You want challengers to the big two? Try sticking a pin in the draw

The Daphne Akhurst Memorial Cup, which goes to the champion, is a trophy that upwards of a dozen women will seriously believe they can win.

Aryna Sabalenka has reached the semi-finals of the last two slams but is mired in some kind of hellish serving groove, having made 74 double faults in her last four matches and lost the last three in a row.

Anett Kontaveit won a tour-high 39 matches on hard courts last year but has only been to one grand slam quarter-final – last year in Australia, losing to Simona Halep.

What about Ons Jabeur, who matched Kontaveit for a tour-high 48 wins across all surfaces last year? The Tunisian is queen of the drop shot, making 147 successful such plays on tour last year, more than any other player, and recently reached the top 10 in the WTA rankings for the first time.

Maria Sakkari reached two slam semi-finals last year, the first of her career, and the form of Barbora Krejcikova and Badosa in the past week in Melbourne marks them out as contenders. Both are recent fast-risers, Krejcikova already with a French Open title to show.

WTA Finals champion Muguruza could be the second Spaniard to twice reach the Melbourne title match, after Arantxa Sanchez Vicario (1994 v Steffi Graf and 1995 v Mary Pierce). Spain has never had an Australian Open women's singles winner: former French Open and Wimbledon champ Muguruza is an authentic contender.

Halep was runner-up to Caroline Wozniacki in 2018, a semi-finalist in 2020 and quarter-finalist last year, and a Melbourne Summer Set title was a handy warm-up for the Romanian. Consider her, too.

Monica Seles, in 1991, was the last player to triumph on her debut in the main draw, but she was already a grand slam winner (1990 French Open). Given the strength of the line-up, the prospect of a bolter coming through this field is unlikely, even if the example of Raducanu tells us anything is possible.

US Open champion Emma Raducanu suffered the heaviest defeat of her professional career at the hands of Elena Rybakina at the Sydney Tennis Classic.

The ninth seed needed just 55 minutes to storm to a 6-0 6-1 victory to set up a meeting with Caroline Garcia in round two.

This was only Raducanu's eighth appearance in a WTA main draw and the 19-year old had not played since November having contracted COVID-19 and then withdrawn from the Melbourne Summer Set last week.

Rybakina lost only 11 points on serve in the match, sending down four aces. Raducanu, by contrast, struggled badly: the Briton gave up six double faults and won just two points behind her second serve.

"My serve is a weapon, so I'm always working on it and trying to find some variety," said Rybakina. "For sure, it's my game to play aggressive and my serve is helping a lot."

Elsewhere in Sydney, Olympic gold medallist Belinda Bencic beat Beatriz Haddad Maia 6-3 6-2 in her first match of the year and will now face France's Oceane Dodin.

Home favourite Ajla Tomljanovic defeated Anna Karolina Schmiedlova in straight sets, while world number 20 Elise Mertens also progressed.

At the Adelaide International 2, Coco Gauff looked in strong form as she dispatched Katerina Siniakova 6-1 6-2, while fellow seed Tamara Zidansek beat Heather Watson in a three-set battle.

There was a shock for top seed Aryna Sabalenka, though, as she fell 5-7 6-1 7-5 to Sweden's Rebecca Peterson, who celebrated her first win over a top-five player, while American Lauren Davis beat seventh seed Jil Teichmann in three sets.

Ninth seed Sorana Cirstea lost in straight sets to Anhelina Kalinina, but eighth seed Liudmila Samsonova beat Mayar Sherif.

Top seed Aryna Sabalenka bounced back from a disappointing defeat in her opening match at the WTA Finals to rally past Iga Swiatek in Guadalajara. 

Sabalenka steadied herself after dropping the opening set and prevailed 2-6 6-2 7-5 Saturday to keep alive her hopes of reaching the semi-finals in her maiden appearance at the event. 

Swiatek, the youngest player in the field at age 20, broke Sabalenka in her final two service games of the first set but could not maintain the momentum as the Belarusian returned the favour in the second. 

Sabalenka entered Saturday with a 9-13 record in three-set matches compared to 35-4 in two-setters but maintained her nerve after the pair traded breaks early in the decider. 

The world number two broke Swiatek to take a 6-5 lead, then served the final game out at love for the victory. 

With Sabalenka's win, Paula Badosa advances to the semi-finals as winner of the group, while the winner of Monday's match between Sabalenka and Maria Sakkari also will advance. Swiatek is out of contention for the semis. 

History is not necessarily on Sabalenka's side, as the top seed has failed to advance from the group stage at three of the past five WTA Finals. 

WINNERS/UNFORCED ERRORS 

Sabalenka – 16/27
Swiatek – 15/18

ACES/DOUBLE FAULTS 

Sabalenka – 8/16
Swiatek – 2/3

BREAK POINTS WON 

Sabalenka – 4/7
Swiatek – 3/7

The 2021 WTA Finals look set to be a fitting end to a fascinating season on the Tour.

The 50th year-ending championships, which will take place in Guadalajara instead of Shenzhen due to coronavirus restrictions, will see eight of the top-10 ranked players come together in two round-robin groups, with four semi-final places up for grabs.

Six of the eight competitors will make their debuts at the event, while only two grand slam finalists from this year – and just one champion – will be present. With world number one Ash Barty withdrawing because of concerns around possible quarantine issues, it really does feel like an open draw.

Stats Perform looks at the eight Finalists and the key data you need to know before the action gets underway...

Group Chichen Itza

Aryna Sabalenka (1)

World number two Sabalenka is the top-ranked competitor in Guadalajara, with 44 match wins this year and titles in Abu Dhabi and Madrid, where she beat Barty.

The Belarusian boasts formidable weapons: Sabalenka has won 71.1 per cent of first-serve points and has an average of 8.4 forehand winners per match on the Tour this season, both of which are best figures among the eight Finalists.

She has only played two matches since losing to Leylah Fernandez in the US Open semi-finals, though, both of which were at last month's Kremlin Cup in Moscow.

Did you know? Since the start of 2018, Sabalenka has won the joint-most matches (three) in WTA Tour main draws after losing the first set 0-6. At the same time, she is 9-13 in three-set contests in 2021.

Maria Sakkari (4)

The nearly-woman of 2021, Sakkari has reached more semi-finals this year (seven) than anyone else on the WTA Tour, including at two of the four slams, but made it to just one final (in Ostrava, where she lost to Anett Kontaveit).

Still, this has been a historic year for the 26-year-old, who became the first Greek woman to reach a major semi-final, enter the top 10 and qualify for the season-ending championship.

Since the start of the US Open, Sakkari has lost only four of 14 matches, a run that includes the semi-final of the Kremlin Cup where she retired due to dizziness.

Did you know? Nobody has won more Tour-level matches against top-10 opponents this year than Sakkari (seven, level with Barty and Jessica Pegula). Before 2021, her record in such matches was 10-13.

Iga Swiatek (5)

Swiatek, the 2020 French Open champion, is the youngest competitor at these Finals at 20 years and 170 days old (as of the tournament's end). She is just the second player born this century to reach this event, after Bianca Andreescu in 2019.

Although unable to get beyond the quarter-finals of a major this year, Swiatek did win titles in Adelaide and Rome, where she inflicted a double bagel on Karolina Pliskova in the final.

Her success in Australia was her first on a hard court, a surface on which she won 19 of 28 matches this year.

Did you know? Swiatek has won 58 per cent (28 of 48) of her matches this season in straight sets, the highest ratio among the Finalists.

Paula Badosa (7)

A successful year for Badosa has been built on clay: she won a Tour-leading 17 matches on the dirt in 2021, reaching the French Open quarter-finals, the last four in Madrid and Charleston and winning the title in Belgrade.

This has been a breakthrough season for the 23-year-old across all surfaces, though, one that culminated in a record-breaking three-set win over Victoria Azarenka in the final at Indian Wells last month.

Badosa clinched that match after a third-set tie-break. She has won four deciding sets in that fashion this year, the most of anyone on the WTA Tour.

Did you know? Badosa has won seven matches (excluding the Olympics) after dropping the first set in 2021. Nobody else has as many come-from-behind victories among the Finalists.

Group Teotihuacan

Barbora Krejcikova (2)

The only major singles champion from 2021 at these Finals, Krejcikova has enjoyed a remarkable rise this year.

Along with success at Roland Garros, where she also triumphed in the doubles, the Czech won titles in Strasbourg and Prague; only world number one Barty (five) and Kontaveit (four) have won more this year.

Among the eight finalists, Krejcikova boasts the highest break-point conversion ratio (49.7 per cent, or 142/286) and break-point saved figure (66.4 per cent, or 150/226) for this season. She has become a clutch competitor and will be hard to stop in Mexico, both in the singles and the doubles.

Did you know? Krejcikova has won six matches against top-20 opponents in her career. All six of those wins were in 2021.

Karolina Pliskova (3)

Pliskova boasts impressive experience of the year-ending event: she is only the fourth player to qualify for five or more WTA Finals since the current format was introduced in 2003 (after Agnieszka Radwanska, Petra Kvitova and Azarenka).

Beaten in her three Tour finals this year, including Wimbledon, the 29-year-old will be desperate to go at least one better than her three consecutive semi-final appearances at this event.

Pliskova begins against Garbine Muguruza, a player she has beaten twice before at the season-ending tournament.

Did you know? Pliskova leads the Tour for aces this season with 364, hitting a year-best 21 in her round-of-16 match with Jelena Ostapenko in Stuttgart. It's the fourth time in the past six seasons Pliskova has been top of the aces standings.

Garbine Muguruza (6)

This is the first time since 2000 that two Spanish players have contested the Finals. Back then, it was Conchita Martinez and Arantxa Sanchez Vicario at Madison Square Garden in New York.

Muguruza, champion in Dubai and Chicago this year, has won more matches on hard courts (34) than anyone else in 2021 aside from Kontaveit. She also boasts the best average for successful net approaches this year (3.0) among the Finalists, which will make her a challenging obstacle in what will be her first Finals since 2017.

The former world number won made a career-high four Tour finals this year and won more than one trophy in a season for just the second time, sending her back into the top 10 for the first time since 2018. 

Did you know? Muguruza boasts a 10-1 record in WTA tournaments in Mexico, winning back-to-back titles in Monterrey in 2018 and 2019.

Anett Kontaveit (8)

With a Tour-leading 37 hard-court wins this year and on a formidable run of form, Kontaveit could spring a surprise at her first Finals.

After losing her fifth match in a row to Ons Jabeur on August 17, the Estonian went on a run of 26 wins from 28 matches, lifted four titles and broke into the top 10 for the first time. It was Jabeur she edged out for a place at this tournament after she won her fourth title of the year at Cluj-Napoca.

Along with Barty, Kontaveit is the only player to reach six Tour-level finals this year, while nobody at the season-ending tournament has won more titles (four).

Did you know? Kontaveit has hit the most backhand winners (293) on hard courts on the WTA Tour in 2021, averaging nearly six per match.

Maria Sakkari admitted she got twitchy before finishing off Simona Halep to reach the Kremlin Cup semi-finals.

The Greek star is chasing what would be just her second career title at WTA level, but the limited silverware belies her growing reputation: Sakkari has shot up to a career-high seventh in the world rankings during her best season on tour.

Looking to finish with a flourish, both in Moscow and next month at the season-ending WTA Finals, Sakkari scored a 6-4 6-4 victory over former world number one Halep on Friday.

The victory sets up a last-four clash with Ekaterina Alexandrova, after the Russian impressed a home crowd by landing a 6-3 6-4 win against top seed Aryna Sabalenka.

Yet Sakkari was almost reeled in by Halep from the point of victory in the second set, being unable to finish off the match on her own serve after building a 5-1 lead. Halep twice broke back, before dropping her own serve.

"It was a very tough match today," Sakkari said in an on-court interview. "It was the first time I'd played Simona, but I knew what to expect: she makes a lot of balls, more than any other player. I had a tough moment in the second set when I was 5-1 up, but finally, I found a way. I got a little nervous, a little bit tired.

"The last couple of months have been tough, I've been travelling a lot so haven't recovered enough. I just tried harder in the last game and just went for it."

Alexandrova's shock win over Sabalenka gave her a sixth career victory over a top-10 player. Second seed Garbine Muguruza followed Sabalenka out of the tournament, walloped 6-1 6-1 by in-form Estonian Anett Kontaveit, who has won 19 of her last 21 matches on tour, including beating Sakkari in the Ostrava final last month.

Kontaveit's semi-final opponent at the WTA 500 event will be Marketa Vondrousova, who claimed a 6-4 6-2 win over Anastasia Pavlyuchenkova.

At the Tenerife Open, Italian Camila Giorgi is the only seeded survivor in the semi-finals. The Italian fourth seed saw off Arantxa Rus 6-1 6-1, with Frenchwoman Alize Cornet and American Ann Li also among Friday's winners at the WTA 250 tournament.

Aryna Sabalenka edged past Ajla Tomljanovic in the Kremlin Cup to reach the quarter-finals in her first match since contracting COVID-19 after the US Open semi-finals. 

Top seed Sabalenka – appearing in Moscow for the first time – had not played since being downed by Leylah Fernandez, having tested positive for coronavirus on the eve of the Indian Wells Open. 

The Belarusian, who sits second in the world rankings, profited from a bye in the first round before battling past Tomljanovic 7-6 (7-2) 4-6 6-1 on Wednesday as she fired 10 aces but made 30 unforced errors. 

Sabalenka will now meet Ekaterina Alexandrova after the Russian cruised past Anhelina Kalinina 6-4 6-1, while Anastasia Pavlyuchenkova comfortably defeated Bernarda Pera 6-2 7-5. 

Number two seed Garbine Muguruza also reached her seventh quarter-final of the season as she defeated Tereza Martincova 6-4 4-6 6-3 in just under three hours in Moscow. 

Meanwhile, Elina Svitolina was shocked in the Tenerife Open as she was dumped out by Maria Camila Osorio Serrano, who succeeded 5-7 6-3 6-2 to claim her first top-10 victory. 

Svitolina was the favourite in Spain and comfortably took the first set on Tuesday. However, inadequate light stopped play and the 19-year-old Osorio responded emphatically the following day to secure a memorable triumph. 

Ann Li coasted past Varvara Gracheva 6-4 6-2 after Anna Karolina Schmiedlova had dispatched Jaqueline Cristian 6-2 7-5 in the opening match of the day. 

Xinyu Wang retired injured against Alize Cornet, who led 4-1 in the decisive set, while Donna Vekic and Irina-Camelia Begu's match was suspended for bad light with the Croatian leading by a set. 

Aryna Sabalenka will not play at Indian Wells after announcing she has tested positive for coronavirus.

In an Instagram Story post, the world number two revealed she feels "okay" while isolating after her COVID-19 result, though is "really sad" not to be playing in the tournament this year.

Sabalenka had been due to return to action for the first time since losing at the semi-final stage of the US Open last month.

"Unfortunately, I've tested positive at Indian Wells and won’t be able to compete," the Belarusian posted on Sunday.

"I've started my isolation and I’ll be staying here until I’m cleared by the doctors and health officials. So far I'm feeling okay but really sad to not be able to play this year."

The absence of Sabalenka is a further blow for the event, considering world number one Ash Barty had already pulled out.

Naomi Osaka is another big-name absentee, along with Serena Williams, while the men's edition is minus Novak Djokovic after the five-time champion opted to withdraw.

Emma Raducanu will be involved, however, after the US Open champion accepted a wild card, while Kim Clijsters has done the same as she prepares to continue her comeback with a first appearance at Indian Wells in a decade.

Andy Murray is a wild-card entrant for the men's tournament, with the main draw beginning on Wednesday.

Aryna Sabalenka said she "destroyed" herself and bemoaned her inability to take opportunities after suffering a shock loss to teenage sensation Leylah Fernandez in the semi-finals of the US Open.

Sabalenka – the second seed – was beaten 7-6 (7-3) 4-6 6-4 to 19-year-old unseeded Canadian Fernandez at Flushing Meadows on Thursday.

The 23-year-old Sabalenka, who has won more matches than any player on the WTA Tour this year, has never reached a major final and her wait continues after also falling in the Wimbledon semis in June.

Sabalenka squandered a set point in the opening set, before losing her final service game to love to bow out on Arthur Ashe Stadium.

"This is life. If you're not using your opportunities, someone else will use it," Belarusian star Sabalenka said at her post-match news conference. "This is what happened today.

"This is what we call pressure. I had a lot of opportunities and I didn't use it. I will try to improve it. I will keep working and fighting, and I believe that one day it will come."

Sabalenka had dominated early, leading 3-0 inside 10 minutes as she barely missed a first serve, before Fernandez rallied to claim the first set.

"I wouldn't say that she did something. I would say that I destroy myself," Sabalenka said. "On the key moment, I was up 4-2 serving, and I think I made double-faults. My first-serve percentage wasn't really good."

Sabalenka identified a key lesson for her was not to "over-think" opportunities, while she was positive about her conqueror Fernandez, who she said was playing like a "top-10 player".

"Now there is no pressure on her at all. Crowd are here for her," Sabalenka said.

"But the question is when you will start to understand what's going on and where you are, how good can you deal with all these expectations and all this level, all this pressure.

"She's like a top-10 player. We'll see how good she will be in the future."

Fernandez will play 18-year-old Emma Raducanu in Saturday's final, marking the first time two teenagers have met in a grand slam decider since Martina Hingis and Serena Williams at Flushing Meadows in 1999.