Roger Federer "is a little uncertain" when he will be back in action just over a fortnight before the US Open gets under way.

The 20-time grand slam winner withdrew from both the Canadian Open and Cincinnati Masters this month as he continues to recover from a knee injury.

Federer has not played since losing to Hubert Hurkacz.in a Wimbledon quarter-final in July and has completed only five events this year.

The legendary Swiss, who underwent two operations on his right knee last year, is unsure if he will feature at Flushing Meadows.

He told Swiss newspaper Blick: "I haven't done anything for a long time because of my knee. After Wimbledon, I had to let everything sink in first.

"This week I'll meet my doctors and my team and then we'll see what happens next. At the moment everything is still a little uncertain."

Federer, who celebrated his 40th birthday last Sunday, remains upbeat despite such uncertainty.

He said: "You have to adapt. It has always been like this in my career. Factors change: degree of awareness, successes, experiences, identity and now just that.

"I'm a quiet guy who takes things with a sense of humour. I always see the good in every situation. If it's not good right now, I know it will get better and it could be a lot worse.

"I am doing very well. My family is healthy. I just turned 40 and I'm still active. Who would have thought it? Certainly not me. I am totally at peace with myself and I am sure that there will be a lot more beautiful things to come."

Novak Djokovic drew level with Federer and Rafael Nadal on 20 major singles titles by winning Wimbledon and the world number one will be bidding to complete a calendar Grand Slam in New York.

Casper Ruud continued his excellent winning streak while Stefanos Tsitsipas made it a birthday to remember at the National Bank Open in Toronto.

Tsitsipas turned 23 on Thursday and marked the occasion with a 6-3 6-2 win over Karen Khachanov.

The Greek star was presented with a cake by tournament officials after his win, as the crowd serenaded him with a chant of 'happy birthday'.

It marks a significant improvement on when Tsitsipas turned 20. On that occasion, he lost the 2018 final of this event to Rafael Nadal.

Next up for Tsitsipas is Casper Ruud, who poked fun at his critics after he eased into the quarter-finals.

Ruud, the world number 12, won three titles on clay courts in July and has now continued that form in the ATP Masters 1000 event.

Playing on a hard court has proved no challenge for the in-form Norwegian, who wrote 'Hard Courts' with a smile underneath on the camera after his 6-4 6-3 victory over Dusan Lajovic on Thursday.

"I have seen a lot of people questioning my ability to play on hard court, so I just thought it was funny to write a little note," Ruud said in a news conference.

"I think it's fun to play on hard courts. Even though I (have achieved) most of my best results on clay, my best slam result is from this year’s Australian Open (where he reached the Round of 16), so I think it's a surface that also can suit my game well even though this year has been mainly clay.

“I think I'm motivated to come back to the hard courts. I have had two very good matches here. It's a great start for me to the hard-court swing."

Ruud, in the hunt for his fifth title of 2021, has won the only previous meeting between the duo.

"[I am] looking forward to that battle," Tsitsipas said. "We have played each other in the past. Not an easy guy to play against. Looking for a change, looking for a switch-up this time."

However, there was no place in the last eight for world number seven - and Olympic gold medallist - Andrey Rublev, who went down 7-5 7-6 (7-5) to American John Isner.

Fresh from a triumph in Atlanta, 36-year-old Isner has looked sharp all week and has now won eight successive matches.

It brings up a third quarter-final appearance for the world number 30 in Canada, and he will play French 11th seed Gael Monfils after he got past lucky loser Francis Tiafoe 6-1 7-6 (7-2). Monfils will be competing in his first ATP Tour quarter-final in 18 months.

Top seed Daniil Medvedev proved too good for Australian qualifier James Duckworth, winning 6-2 6-4 in one hour and eight minutes.

Medvedev was in ominous form on the hard court, sending down 10-1 aces and winning 27 of 32 points on his first serve.

The Russian world number two will play seventh seed Hubert Hurkacz who fought back to win 6-7 (7-9) 6-4 6-4 over Nicolas Basilashvili.

Eighth seed Diego Schwartzman lost in three sets to 10th seed Roberto Bautista Agut after the Spaniard saved three match points.

Bautista Agut will next play Reilly Opelka who came from behind, and also saved a match point, to win over Lloyd Harris in three.

Canadian fifth seed Denis Shapovalov was a major casualty in the second round of the National Bank Open in Toronto after a straight-sets defeat to Francis Tiafoe.

Unseeded American Tiafoe swept aside the local 6-1 6-4 in one hour and 15 minutes to secure his third-round spot against 11th seed Gael Monfils who beat John Millman 3-6 6-3 6-4.

Tiafoe was only in the Toronto main draw as a lucky loser after being defeated in qualifying by Emil Ruusuvuori but he hit 14 winners in an emphatic display.

World number 10 Shapovalov was unable to generate any break points while Tiafoe reeled off five games in a row, with two breaks, to win the first set.

The Canadian continued to struggle with his serve in windy conditions, as the American world number 52 won 88 per cent (23/26) of points on his first serve.

Another local hope, ninth seed Felix Auger-Aliassime, also was eliminated, going down 7-5 6-4 to Serbian Dusan Lajovic.

The Canadian hit six aces to Lajovic's none, but was undone by unforced errors at key times, with a double fault gifting the Serbian a 6-5 lead in the opening set.

Australian 12th seed Alex de Minaur also bowed out after a one-sided 6-1 6-1 defeat to Georgian world number 42 Nicolas Basilashvili.

Basilashvili sent down 6-2 aces and converted five of his six break points generated in an impressive display.

Australian qualifier Jack Duckworth booked a third-round ticket against top seed Daniil Medvedev after upsetting 16th seed Jannik Sinner, who won last week's Citi Open.

Fourth seed Andrey Rublev won through with a 7-6 (7-4) 6-3 victory over Fabio Fognini, while seventh seed Hubert Hurkacz progressed with a walkover after Kei Nishikori retired with a shoulder injury.

Eighth seed Diego Schwartzman beat Benoit Paire 7-5 6-1, while 10th seed Roberto Bautista Agut handled Tommy Paul 6-3 6-4.

John Isner knocked out 13th seed Cristian Garin in three sets, while Lloyd Harris beat Feliciano Lopez in two and Karen Khachanov defeated compatriot Aslan Karatsev 7-6 (9-7) 6-4 to secure a third-round meeting with third seed Stefanos Tsitsipas.

Tsitsipas pledged to help those affected by the fires in his homeland in his post-match press conference on Tuesday.

“My heart is with all the people of Greece,” Tsitsipas said. “I come from the south suburbs of Athens. When I was there a few days ago, I could see the fires from the south. Huge, giant clouds, smoke, which you could see from far, far away. It wasn't very nice. Even at the beach that day when I went to swim, you could see all the debris from the smoke and from the fires in the sea.”

Daniil Medvedev and Stefanos Tsitsipas survived three-set scares at the National Bank Open on Tuesday, but five-time tournament champion Rafael Nadal departed Toronto without even taking the court. 

Top seed Medvedev, who won just three games against Nadal in the final in 2019, the last time the tournament was played, prevailed 4-6 6-3 6-4 in his opener against Alexander Bublik.

The man Nadal beat to win the title the previous year, Tsitsipas, failed to convert on five match points in an epic second-set tiebreak but recovered to down Ugo Humbert 6-3 6-7 (13-15) 6-1.

Nadal pulled out ahead of a scheduled match against Lloyd Harris, who beat him last week in Washington as the 20-time grand slam winner struggled with a foot injury. 

Countryman Feliciano Lopez replaces Nadal in the draw and will face Harris on Wednesday. 

Elsewhere Tuesday, sixth seed Casper Ruud needed more than two hours to put away Marin Cilic 6-3 3-6 6-3, while 14th seed Grigor Dimitrov suffered a quick 6-3 6-4 exit against big-serving American Reilly Opelka.

A pair of unseeded veterans advanced, with 2016 finalist Kei Nishikori a 6-4 6-7 (5-7) 6-2 winner over Miomir Kecmanovic and John Isner defeating Alejandro Davidovich Fokini 6-4 6-1 in just over an hour.

Two days after appearing in his first ATP Tour final at the Citi Open, Mackenzie McDonald fell 6-3 6-4 to Benoit Paire in his Toronto opener. 

In other first-round matches, Karen Khachanov beat Cameron Norrie 6-4 5-7 6-4, Frances Tiafoe downed Yoshihito Nishioka 6-4 6-3, Dusan Lajovic handled Emil Ruusuvuori 3-6 6-3 6-3 and Nikoloz Basilashvili defeated Jenson Brooksby 2-6 6-0 6-4.

Rafael Nadal has withdrawn from the National Bank Open ahead of his opening match due to a left foot injury.

The Spaniard made a return to action on the ATP Tour last week at the Citi Open, his first outing since suffering defeat to Novak Djokovic in the semi-finals of the French Open in June.

His comeback was aimed at getting prepared for the US Open but, having lost in the last 16 in Washington to Lloyd Harris, he will not now be participating in Toronto.

"I really wanted to play here a lot, but now is the moment to make a decision, and this is unfortunately the decision that I have taken," Nadal told the media.

"I have had this issue for a couple of months, as people know.

"Of course, it is not a happy situation after all the success that I had here in Canada, not being able to play this year after missing a year. It's a tough one, but that's how it is today."

Nadal skipped Wimbledon citing the need to recover after the clay season, while the left-hander also opted out of representing his country at the Tokyo Olympics.

The five-time champion in Toronto was scheduled for a repeat meeting with Harris in the second round. Instead, his place in the draw goes to compatriot Feliciano Lopez.

South African Lloyd Harris booked a second-round date with Rafael Nadal at the National Bank Open after a straight-sets win over Canadian qualifier Brayden Schnur on Monday.

World number 49 Harris eased past Ontario-born Schnur 6-3 6-2 in one hour and 17 minutes in Toronto.

Harris sent down nine aces, winning 78 per cent of points on his first serve, converting four from four break points on return.

Nadal is a five-time champion in Toronto, winning the previous two editions in 2018 and 2019.

Marin Cilic, who won his first title for three years in Stuttgart, beat Albert Ramos-Vinolas 6-2 4-6 6-3 in two hours and 13 minutes.

The 32-year-old will face sixth seed Casper Ruud in the next round.

Fabio Fognini also needed three sets to progress, battling from behind to defeat Jan-Lennard Struff 6-7 (2-7) 6-2 6-4 to set up a meeting with Andrey Rublev.

Ugo Humbert impressed in his straight-sets defeat of Lorenzo Sonego and will next face third seed Stefanos Tsitsipas, while qualifier James Duckworth beat Taylor Fritz to secure a showdown with Citi Open winner Jannik Sinner.

Alexander Bublik defeated Briton Dan Evans in straight sets to earn a second round meeting with top seed Daniil Medvedev, while Australian John Millman will face 11th seed Gael Monfils after beating Ricardas Berankis.

Reilly Opelka came from a set down to win over Australian Nick Kyrgios, while Tommy Paul also fought back to beat Canadian Vasek Pospisil.

Novak Djokovic will not play at the Western and Southern Open after a "taxing" run that has brought him to the brink of a calendar Grand Slam.

The world number one's bid for a Golden Slam faltered at the Olympic Games as he lost to Alexander Zverev in the semi-finals in Tokyo.

Djokovic appeared to tire badly and finished fourth in both the men's singles event and the mixed doubles, opting out of the bronze medal match in the latter.

But victories at the Australian Open, French Open and Wimbledon mean 2021 is still on course to be the best year of Djokovic's career.

And the Serbian is taking a little time to prepare himself for the final push at Flushing Meadows, meaning no appearance in Cincinnati next week.

"Dear fans," he wrote on Twitter. "I wanted to share with you that I am taking a bit longer to recover and recuperate after quite a taxing journey from Australia to Tokyo.

"Sadly, that means I won’t be ready to compete in Cincinnati this year, so I'll turn my focus and attention to the US Open and spend some more time with family.

"See you in New York soon!"

Former world number one Andy Murray has been handed a place in the main draw of the US Open after Stanislas Wawrinka pulled out.

Murray, the 2012 champion at Flushing Meadows, reached the second round of the event last year, which was won by Dominic Thiem.

The 34-year-old, who competed in the men's doubles at the Tokyo Olympics, has only played eight Tour-level matches in 2021. He was handed a wildcard for Wimbledon, where he lost in the third round to Denis Shapovalov.

Novak Djokovic is due to lead a strong men's field for the tournament in August, which will be played in front of capacity crowds.

The world number one is seeking to become the first man to win all four major championships in the same year since Rod Laver in 1969.

Rafael Nadal and Roger Federer, who are tied with Djokovic on 20 grand slam singles titles, are also set to play.

Wawrinka, himself a champion in New York in 2016, is still recovering from his second foot surgery of the year.

Roger Federer turned 40 on Sunday amid uncertainty over whether he will grace the stage of a grand slam again.

Both he and Serena Williams, who reaches the same birthday landmark in September, have kept their future plans under wraps.

However, it would come as no surprise now if one, or both, were to retire by the end of the year.

Injuries are taking their toll, and even the greatest champions cannot go on forever.

Stats Perform looked at both Federer and Williams, considering what they may still want to achieve, and their prospects of attaining those remaining goals.

Federer's final fling?

Ahead of his 30th birthday, Federer was asked what it felt like to hit such a milestone.

"Birthdays happen. They're part of life," Federer said. "I'm happy I'm getting older. I'd rather be 30 than 20, to be honest. To me it's a nice time."

A decade on, Federer has good reason to be satisfied with life as he chalks up another decade. Family life is good, he'll never need to borrow a dollar, and he has advanced from 16 grand slams to 20.

But the knees would sooner be 30 than 40, and Federer, remarkable sportsman though he is, looks to have entered the lap of honour stage of his career – if he can even complete such a lap.

Two knee operations in 2020 were followed by a setback that ruled him out of the Olympics and will also keep him sidelined for the Toronto and Cincinnati tournaments before the US Open.

Will Federer make it to Flushing Meadows, where he won five successive titles at the height of his career? There has to be doubt over that, and should he indeed be an absentee in New York, what is there left to target? The Laver Cup, perhaps, a tournament in which he is financially invested and which is due to be played in Boston in late September.

Would he play on in 2022? Could he tolerate more long road trips without his family, living in a tennis bubble?

Target: Federer has never settled for second best, and it may have dawned on him at Wimbledon that in all probability he no longer can win a grand slam. Losing a 6-0 set to Hubert Hurkacz on the way to a quarter-final exit would have hurt. The hunger does not go away after 20 grand slams, but Federer's battle-weary body is sending him messages. He will want to go out on his own terms, which means getting fully fit.

Prospects: Assuming the knee issue is not a major problem, and more of a niggle, then Federer could still play the US Open, Laver Cup, Indian Wells and Paris Masters this year. If the mind is willing but the body does not comply, however, then it would not be a shock to see him call time before the Australian Open comes around in January.

Serena still one short of Court

From precocious teenager to queen of the tour, Williams' tennis journey has been a 25-year odyssey and there is nobody more driven to succeed than the great American.

It is an intense frustration that she remains rooted on 23 grand slams, one short of Margaret Court's record haul, and the four grand slam final losses she has suffered while on that mark have been cruel blows.

As her 40th birthday approaches on September 26, prospects of matching Court are fading. The leg injury that cruelly forced her out of Wimbledon in the first round was a harrowing turn of events, given she looked primed to be a big title challenger in London.

She is becoming less of a factor when looking at title favourites, but Williams is still capable of beating top players, still a threat wherever she shows up. It comes down to whether the body lets her chase her goals, and whether the pain of so many near-misses in recent years persuades this great champion the exertion is no longer worth prolonging.

Target: The 24th slam has been the must-have for Williams. Tour titles feel like an irrelevance, and Williams has won just one of those since January 2017, her calendar built around peaking for the majors since returning from giving birth to daughter Olympia.

Prospects: Beating Aryna Sabalenka and Simona Halep at the Australian Open demonstrated Williams still has the game for the big stage, and a semi-final defeat to Naomi Osaka, to whom she has now lost in three of four encounters, should not particularly detract from that. Wimbledon felt like a golden opportunity, with a host of major rivals absent and others struggling for form. There is no doubt she felt that way. Getting to 24 – and beyond – has shifted from feeling like an inevitability to being an odds-against chance now.

Novak Djokovic led the ATP Tour's birthday message to Roger Federer, as the Swiss star celebrated his 40th on Sunday.

Federer, ranked ninth in the world, made his professional debut in 1998. He has gone on to win 20 grand slam titles, a feat matched by only Rafael Nadal and Djokovic, who tied his rivals with his triumph at Wimbledon in July.

His first grand slam title arrived at Wimbledon in 2003, when Federer was aged just 21. In 2004, 2006 and 2007, he won three out of the four majors on offer.

Federer has six Australian Open titles, eight Wimbledon triumphs, five US Open wins and one French Open success to his name, while he has also won six ATP Tour Finals.

Djokovic and Federer have met 50 times on the ATP circuit, with the Serbian shading their head-to-head record with 27 wins – their most recent encounter coming in the semi-finals of the 2020 Australian Open.

Yet it was he who led the tributes to a true great.

"Hey Roger, happy 40th birthday – 40th, wow, what a milestone! You still keep on inspiring and thriving on the court, off the court, inspiring all of us," Djokovic said in a video posted to the ATP Tour's official Twitter account.

"It's been a huge honour to share the tennis court and the tennis circuit with you in the last 15 years.

"Hopefully you can still keep on playing. The sport needs you, of course, and thanks for everything you have done and thanks for showing us that even at that age we can play at a very high level.

"All the best, I wish you health and love and happiness with your close ones and thanks again for everything."

Kei Nishikori, who has beaten Federer three times and suffered eight defeats to the Swiss, was next up.

"Roger, happy 40th birthday!" Nishikori said.

"You are still my idol, I always looked up to you and I hope we can play a couple more times and I hope you can still keep going and win grand slams."

World number 15 Felix Auger Aliassime shares his birthday with Federer, though the Canadian is some 19 years junior.

"Hey Roger, the big 40, while I'm just turning 21," he said. "It's amazing for the sport that I'm playing and you're still playing at the same time.

"I hope I'll still be playing when I'm 40 as well. Thank you for everything you've been doing for tennis, it's so good to still have you around, I hope you have a great birthday."

Roger Federer has withdrawn from both the Canadian Open and Cincinnati Masters as he continues to recover from a knee injury.

After undergoing two operations on his right knee last year, Federer has competed in just five events so far in 2021.

Most recently, the 20-time Grand Slam champion reached the Wimbledon quarter-finals, before losing in straight sets to an inspired Hubert Hurkacz.

The 39-year-old then missed the Olympic Games due to what he described as a "setback" with his knee.

He was scheduled to appear in Toronto and Cincinnati – where he is a seven-time winner – and step up his preparation ahead of the US Open.

However, his participation in the final Slam of the year is now uncertain after he pulled out of this month's ATP Masters 1000 tournaments.

Another player who will not be competing in Toronto is Alexander Zverev; the Olympic gold medallist also opting to withdraw.

In a statement, he said: "Due to the intense past couple of weeks and my incredible experience at the Olympics, I need to recover so that I can hopefully be at my best for the remainder of the U.S. summer swing.

"It was a difficult decision for me as I have had great memories from Canada and I can't wait to be back next year!"

Alexander Zverev followed up his stunning win over Novak Djokovic by storming to Olympic gold in the men's singles final.

A thumping 6-3 6-1 victory against Russian Olympic Committee's Karen Khachanov was the perfect way for world number five Zverev to land the biggest title of his career.

He won 10 of the last 11 games of his semi-final against world number one Djokovic and carried that form into Sunday's title match, brushing aside the threat across the net.

It makes him Germany's first men's singles champion at the Olympics. Steffi Graf won the women's title as part of a calendar Golden Slam in 1988, and four years later Boris Becker and Michael Stich teamed up to take doubles gold.

For the man who won the ATP Finals in 2018 and reached last year's US Open title match, this marked a step forward in a career many expect will eventually feature grand slam titles.

He secured a swift break in the first set against Khachanov, who was outstanding in the semi-finals against Pablo Carreno Busta but could not impose his game in the gold-medal match.

Another break followed and the set was gone in 43 minutes.

The second set rushed by in a mere 36 minutes, with Zverev against striking early and never looking back.

He created two break points in the second game of that set, and although Khachanov saved them, a third soon followed and the Russian netted on the forehand.

The momentum was all one way and there was never a moment when Khachanov, ranked 25th by the ATP, looked as though he might pose some danger. 

Zverev gave himself a first match point when he punched away a backhand volley, and the glory belonged to the German when Khachanov slapped a forehand into the net on the next point.

BENCIC DENIED GOLDEN DOUBLE

Belinda Bencic was the surprise champion in the women's singles and the Swiss had a chance to land a second gold medal on Sunday when she and Swiss partner Viktorija Golubic lined up in the doubles final.

It was not to be for Bencic and Golubic, however, as they were soundly beaten by the prolific Czech pair of Barbora Krejcikova and Katerina Siniakova.

A 7-5 6-1 win for the reigning French Open champions meant Bencic and Golubic were left with the silver medal.

But there was little in the way of regret for the Swiss pair, with Bencic showing off both her gold and silver medals after the match, saying: "We are overjoyed. We will fly back on Monday with other medallists. It's a great feeling to know people are waiting and they acknowledge the medals we won for our country.

"The week here was incredibly beautiful. We experienced so many emotions, and it's great to go back and share all of these emotions with everyone at home.

"It's not just about the medals or the titles, it's about the memories you create that will last forever. To share this with Viki is unbelievable.

"The whole week I never felt like I was in a normal tournament or playing alone. She was alongside me the entire way. I always tell her we won this gold medal together as well. When we will be 80 years old and have a coffee, we will talk about this moment and I cannot wait for that."

Casper Ruud captured his third title on clay in as many weeks after defeating Pedro Martinez 6-1 4-6 6-3 in the Generali Open final on Saturday.

The world number 14 continued his blistering form having also landed the Swedish Open and Swiss Open earlier this month.

The Norwegian has now won each of his last 11 matches since defeat by Jordan Thompson in the opening round at Wimbledon.

Ruud – also a winner at the Geneva Open in May – dominated the opening set against world number 97 Martinez, who was appearing in his first ATP final.

The Spaniard defeated second seed Roberto Bautista Agut on the way to reaching the showpiece, and responded well by taking a close second set.

Nevertheless, Ruud broke to take control of the decider, before closing out victory for a fourth ATP title of the season – all of which have come on clay.

Novak Djokovic blamed mental and physical exhaustion after another desperate day for the Serbian at the Olympic Games meant he will leave Tokyo empty-handed.

The world number one lost 6-4 6-7 (6-8) 6-3 to Pablo Carreno Busta in the singles bronze medal match, smashing one racket against a net post and tossing another into the stands in gestures of frustration.

Djokovic then cited a shoulder injury as he pulled out of the mixed doubles third-place match. That decision meant Ash Barty and John Peers of Australia took bronze, with Djokovic and his unfortunate Serbia partner Nina Stojanovic finishing fourth.

"I am dealing with injuries. Not one, more than one," Djokovic said in an interview with Serbian media, according to tennismajors.com. "I hope that it won't stop me from going to the US Open, which is my next big goal.

"I feel bad for Nina because we did not fight for a medal in mixed, but my body said 'enough'. I have played under medications and abnormal pain and exhaustion."

The 34-year-old Djokovic said he had put his "very last source of energy" into the tournament and was satisfied with his effort, with a semi-final defeat to Alexander Zverev on Friday having left him resigned to a battle for what by his standards was perceived as a consolation prize.

But Djokovic added: "I know I've not played well today, and yesterday in the second and third set.

"The exhaustion, both physical and mental, got to me and it's unfortunate that in the most important matches I just didn't deliver, but I gave it all."

Djokovic suggested the Paris Olympics in 2024 were a possible target, although he must be becoming sick of Olympic tennis by now, having only one bronze to show for four attempts to win gold.

He took bronze in 2008 but lost to Argentina's Juan Martin del Potro both in the third-place match at London 2012 and the first round at Rio 2016.

Now there is more Games agony to digest, as well as a need to reboot ahead of the upcoming North American hardcourt swing and that US Open campaign. His hopes of a calendar Golden Slam are over but a sweep of the grand slams remains a possibility, having already landed the Australian Open, French Open and Wimbledon titles.

"I've had some heart-breaking losses at the Olympics Games," Djokovic said. "I know that those losses have usually made me stronger. I know that I will bounce back. I will try to keep going for the Paris Olympic Games. I will fight for my country to win medals."

Carreno Busta's reaction was thoroughly refreshing, with the Spaniard jubilant to secure a medal.

He said: "This week has been a very harsh week mentally for me. When I saw Novak lost, and I had to play him for this medal, I had my doubts.

"But last night I slept like I haven't slept in Tokyo. I slept for nine hours straight, that was an advantage to me. I came on to the court today knowing Spain was behind me.

"This is even more incredible than winning other tournaments. I've won Davis Cup, I've gone far in other tournaments, but winning an Olympic medal is indescribable. Words fail me, I felt Spain rallying behind me. A bronze medal is a dream come true for me."

The knock-on effort of Djokovic's withdrawal from the mixed doubles meant Barty and Peers added to Australia's medals haul without having to step on court for the third-place play-off.

Barty insisted she and Peers were worthy bronze medallists, saying: "It's incredible. It's unique circumstances and heartbreaking for Team Serbia not to get out on court.

"But for Johnny and I this is a dream come true for us. I feel like we've really deserved this one."

Novak Djokovic smashed one racket and threw another into the stands on the way to losing his bronze medal match at the Tokyo Olympics on Saturday.

Spain's Pablo Carreno Busta beat the world number one 6-4 6-7 (6-8) 6-3 to finish third in men's singles.

The shock result followed a day on from Djokovic's hopes of a Golden Slam being crushed by defeat to Alexander Zverev in the semi-finals.

In the wake of his singles third-place match setback, Djokovic also pulled out of the mixed doubles bronze match, citing a left shoulder injury.

Having already clinched the Australian Open, French Open and Wimbledon titles, Djokovic was eyeing gold at the Games before heading to the US Open in August, aiming to land the five biggest prizes in tennis in the same season.

That has never been achieved in a calendar year by a man, and Djokovic could not even manage a consolation prize from his singles mission in Japan. How serious his injury is now remains to be seen.

After levelling the singles match by taking the second-set tie-break, Djokovic boiled over in the first game of the decider, firstly when flinging his racket several rows back from the middle of the court after Carreno Busta put away a volley at the net.

Djokovic picked another racket from his bag but petulantly demolished that against a net post after dropping the third game to slide 3-0 behind, receiving a warning from the umpire for that violent outburst.

His anger may have been explained by injury or by his disappointment on Friday, when, as well as losing to Zverev, Djokovic and Serbian team-mate Nina Stojanovic were beaten in the semi-finals of the mixed doubles.

Djokovic would have had one final shot at a medal from his Tokyo trip to come later on Saturday, with the 34-year-old and Stojanovic due to face Ash Barty and John Peers in another match for bronze.

However, shortly after his singles exit, it was announced that Djokovic had pulled out of that match, handing Barty and Peers the medal.

Amid the anger and frustration exhibited on court by Djokovic, it was a banner day for Carreno Busta, as Spain celebrated another tennis medal, having won at least one in eight of the last nine Olympics.

The 30-year-old fell to the court in joy at the end of the two hours and 47 minutes it took him to defeat the world number one, his elation a sharp contrast to the emotions of his beaten opponent.