Alexander Zverev believes his comeback victory over Novak Djokovic at the Olympics has paved the way for his fine start at the US Open.

Zverev came from a set down to defeat world number one Djokovic 1-6 6-3 6-1 at the semi-final stage in Tokyo, with the German going on to claim gold by beating Karen Khachanov in straight sets.

The world number four carried the winning form to Cincinnati, triumphing at the Western and Southern Open, and has made a smooth start at Flushing Meadows, where he lost out to Dominic Thiem in last year's final.

Zverev did not offer up a single break point in a dominant first-round win over Sam Querrey, and lost only four games when cruising past Albert Ramos-Vinolas 6-1 6-0 6-3 on Thursday.

"The process started at the Olympics for me, and the match against Novak," Zverev told reporters.

"That kind of started it off, because I was down badly, and I managed to win with great tennis.

"It was very important for me to kind of back it up in Cincinnati, because a lot of the times players that for the first time in their career win something really big like a grand slam title or a gold medal, they do tend to go downhill a little bit.

"So it was important for me to go to Cincinnati, to a place where I have never won a match before this year, and have a great tournament."

Another motivation for Zverev is the cruel fashion in which he lost to Thiem last year, when he surrendered a two-set lead.

"I mean I was the first man in 785 years to lose a US Open from two sets to love up and being a break up in the third set, serving for it in the fifth set, being two points away multiple times, it was painful," Zverev said with a smile.

"I still remember it, I remember it every single time I walk on this board but I take it as motivation because I'm back here to hopefully play a great tournament and win a grand slam title, that's what I’m here to do."

Zverev has now tallied up 40 wins in 2021 and 13 on the bounce, though the 24-year-old - who could meet Djokovic in the semi-finals - knows he has to maintain his strong service game to keep his best tennis.

"My serve is kind of the key to my game. When it's working I'm playing great. When it's not, I'm losing matches like I did at Wimbledon," he said.

"It's no secret that my serve is probably the most important shot in my game, and I'm happy with how it's working. The matches are not going to get easier and I will need that to be my weapon.

"I think it was always a problem of mine at the beginning of my career that I always spent a lot of hours, a lot of time in the beginning of grand slam tournaments. So it's nice to have two matches, winning [them] in straight sets."

Stefanos Tsitsipas has defended his "personal need" for long bathroom breaks after being jeered during his four-set second round win over Adrian Mannarino at the US Open on Wednesday.

The world number three triumphed 6-3 6-4 6-7 (4-7) 6-0 but was booed by the Arthur Ashe Stadium crowd after taking a bathroom break which exceeded seven minutes.

The Greek was criticized by Andy Murray, who said he lost respect for Tsitsipas after taking a lengthy break ahead of the final set in their five-set first round epic on Monday.

Alexander Zverev weighed in on the discussion, claiming Tsitsipas was communicating with his coach during his bathroom breaks, labelling them "ridiculous" and saying he had broken an "unwritten law".

Tsitsipas reverted to the rule book in his defence after beating Mannarino, insisting he had done nothing illegal and longer breaks were part of his "personal needs".

"It's just my personal needs," Tsitsipas told reporters. "Some people have other needs. Some people take much more than 25 seconds between points, which is fair.  

"I've done everything the right way. If I haven't I should be penalized. I completely agree with it. I should get a fine or be penalized if I haven’t followed whatever I've done correctly. But as far as I know, it is a necessity, it is a need when I'm out there playing and performing."

Tsitsipas said he felt fans who booed and jeered did not understand the game or his need to take longer bathroom breaks.

"I haven’t done anything wrong so I don't understand," he said. "The people love the sport, they come to watch tennis. I have nothing against them. But some people don't understand. They haven't played tennis at high level to understand how much effort and how much difficult it is to do what we are doing."

He added: "It is important. First of all, you carry less weight on you with all the sweat. You feel rejuvenated, you feel fresh, and you don't have all the sweat bothering you and coming in your face, on your fingers, everywhere all over your body. It makes you feel better.

"For me it is important to take that break. For someone else probably not. And everyone has his own time. I try and be as quick as I can. Sometimes I just need a bit more time."

Tsitsipas added that he was taken aback by the public criticism from Murray and Zverev.

"I never complain of what other players do," the 23-year-old French Open runner-up said. "My parents have taught me not to watch other people's business and concentrate on myself. Do my job.

"I just don’t understand when some players go and criticize other players, or during a match they put too much emphasis on it."

There have been calls for a hard cap on the permitted time for bathroom breaks, which American Sloane Stephens agreed with, speaking after her straight-sets win over 21st seed Coco Cauff.

"I don't think you should be gone from the court for six-eight minutes," Stephens said. "It's a long time to leave a match. That changes the whole momentum of a match.

"I can't speak for what happened in that match, but I do know on the girls' side, there still is a lot of that. It's gamesmanship.

"I think there definitely needs to be a rule or changes. They make a lot of rule changes for smaller things, like they took one minute off the warmup. If someone goes to the bathroom for nine minutes, no one says anything."

Alexander Zverev has accused Stefanos Tsitsipas of behaving like a junior and disrespecting his opponents by taking such long bathroom breaks during matches.

Andy Murray was furious when Tsitsipas was off court for around eight minutes ahead of the final set in their thrilling first-round match at the US Open on Monday.

Tsitsipas also required a medical timeout for a foot problem during a pulsating contest that the world number three won 2-6 7-6 (9-7) 3-6 6-3 6-4 at Flushing Meadows.

Murray said he had lost respect for the 23-year-old, who defended his lengthy spell off court and stated he had played by the rules.

The Brit was in no mood to back down on Tuesday, however, as he tweeted: "Fact of the day. It takes Stefanos Tsitsipas twice as long to go the bathroom as it takes Jeff Bezos to fly into space. Interesting."

Zverev appeared to accuse Tsitsipas of communicating with his father and coach, Apostolos, when he took a break during their semi-final showdown at the Western and Southern Open in Cincinnati this month.

Tsitsipas responded by denying having ever used his phone during such a situation, describing the accusation as "absolutely ridiculous."

However, world number four Zverev had Tsitsipas in his sights once again after beating Sam Querrey 6-4 7-5 6-2 in New York.

The German said: "It's happening every match. It's not normal. It happened to me in the French Open, to Novak at the finals [of the] French Open. I think Hamburg against [Filip] Krajinovic he was complaining, against me in Cincinnati was ridiculous, and now here again. I think players are catching up with that.

"He's the number three player in the world. I do not believe he needs to do that, because if you're top three in the world, you're one of the best in the sport.

"These kind of things happen at junior events, at Futures, at Challengers maybe, but not when you're top three in the world.

"You're allowed to do that but it's like an unwritten rule with players. I have been breaking rackets, I go insane sometimes and all that but one thing I'm very proud of, and I'll keep for the rest of my career, is I win and I lose by playing tennis on the tennis court."

Zverev reiterated his grievance with Tsitsipas having taken such a lengthy break during their meeting in Cincinnati.

"I didn't ask that question in Cincinnati, which I was very surprised at, because I was going to answer that very truthfully and honestly," he said.

"He's gone for 10-plus minutes. His dad is texting on the phone. He comes out and all of a sudden his tactic completely changed. It's just not me but everybody saw it. The whole game plan changes.

"I'm like, either it's a very magical place he goes to or there is communication there. But I also don't want to disrespect him. He is a great player, he is number three in the world for a reason. He's winning tournaments and playing incredible tennis this year for a reason, so it's not only that.

"But I do believe, and Andy said it as well, there is some level of respect that everybody needs to have between players.

"I feel like sometimes - or he might just go to the toilet. We don't know that, that's also possible. But it just happens too often, I would say."

Alexander Zverev believes world number one Novak Djokovic remains the favourite for the upcoming U.S. Open despite the German backing up his Olympic gold medal with victory in Cincinnati.

The German world number four defeated Andrey Rublev in straight sets on Sunday to win the Western and Southern Open, claiming his fourth title of the ATP season.

The 2021 U.S. Open begins next Monday with Dominic Thiem, who defeated Zverev in the 2020 final, withdrawing from the men's draw along with superstar Roger Federer and Rafael Nadal.

Their absences have opened up an opportunity for the in-form Zverev to have a run at the title but the German insisted Djokovic, who he defeated in the Olympic semi-finals, is the player to beat.

"I do think that he's still the favourite," Zverev told reporters after his win in Cincinnati.

"I do think he's going to be playing incredible tennis there. He's going to be fresh, and I think there is also other guys that are in very good form. I think Rublev is in very good form, [Daniil] Medvedev, [Stefanos] Tsitsipas, all those guys are playing great tennis.

"It's definitely going to be an interesting US Open. But I'm also looking forward to it, because I know where I stand, I know how I'm playing, and I hope I can continue the work and hopefully play even better in New York."

Djokovic has not played since Tokyo 2020, where he lost his bronze medal match to Pablo Carreno Busta after his semi-final defeat to Zverev.

The Serbian world number one opted to withdraw from the mixed doubles' semi-final afterwards, citing a left shoulder injury.

"I think Novak will be back. He's obviously going to be the favourite but I think other guys are going to be in great shape,” Zverev said.

"I'm looking forward to the week. Let's see how it goes. But there is still one week to go. I still have a lot of work ahead of me. I have to find my rhythm in New York, as well."

Zverev, who had never won a match in Cincinnati prior to this year's event, has not lost a match since his Wimbledon fourth-round exit to Felix Auger-Aliassime in July.

Alexander Zverev claimed his fourth title of 2021 with a 6-2 6-3 victory over Andrey Rublev to win the Western and Southern Open.

The Olympic champion had not won a match in Cincinnati prior to this year's tournament, but Sunday's one-sided final capped a remarkable turnaround for the world number five.

Zverev raced into a 4-0 lead before securing the opening set 6-2 as he produced no errors across the first seven games.

The third seed carried on his domination, breaking Rublev in his opening service game of the second set to pave the way for the 17th ATP title of his career within an hour in the showpiece.

After paying tribute to "his best friend on Tour" Rublev, Zverev added in his on-court interview: "It is incredible that tennis can be back, sport can be back, and we can watch and play this beautiful sport again.

"I normally do not look forward to this week - not winning a single match in seven years - but this has now become one of my favourite times of the year for me, hopefully it can be for the next 10 to 15 years."

The 24-year-old reached the final of the US Open last year, though he will now eye going one step further as the tournament commences at the end of August.

Andrey Rublev finally got the better of compatriot Daniil Medvedev after a flashpoint involving a courtside camera in the Western and Southern Open semi-finals.

Rublev will now face Alexander Zverev in the decider, having ended Medvedev's bid for a Toronto-Cincinnati double.

Medvedev had never even dropped a set to his fellow Russian in four prior ATP Tour meetings and appeared to be on course for another dominant victory when he took the first set.

But the world number two clattered into a camera early in the second and all momentum was soon lost.

Medvedev complained about the positioning of the camera, claiming it had caused a hand injury and aiming a kick at the lens.

He swiftly called for treatment as his performance started to fall well below his lofty standards, with Rublev finally able to win a set after breaking in an epic 15-minute game.

A series of unforced Medvedev errors allowed Rublev to break again in the decider and seal a stunning 2-6 6-3 6-3 triumph.

Third seed Zverev fought back from a double break down in the final set to progress to the final with a 6-4 3-6 7-6 (7-4) win over second seed Stefanos Tsitsipas.

The epic match lasted two hours and 41 minutes, with Zverev responding strongly after appearing unwell to book his spot in the final against Rublev.

Rublev gets his Daniil degree

Asked to reflect on finally toppling Medvedev, Rublev told Amazon: "It's always tough to play against Daniil and to beat him.

"I think it gives me a bit more confidence that I can play against him, I can compete against him. There are still so many things to improve, but it's like I've passed university."

The victory came as a relief, with Rublev believing he was unfortunate even to be trailing in the first set.

"Inside I was thinking, when I was 6-2, the score shouldn't be like this," he said.

"The points were really tight, some little outs, little mistakes, some good shots from Daniil. The score was not real [in] the first set.

"Even the third set, I won 6-3 but the match was so intense. You saw so many rallies, so many long rallies, and it was so tough.

"It was a super mental match, a super physical match, exactly like a chess match."

Zverev's Novak mentality

Tokyo 2020 gold medalist Zverev had trailed 4-1 in the third set against Tsitsipas, but fought back with two breaks before winning in a tie-break.

"After I did the first break back I thought 'OK I have the chances'," Zverev said during his on-court interview. "I felt like he was not serving bombs. I felt like I was always in the rallies but I was losing the rallies because I was a bit low energy, so I started being a bit more aggressive, a bit of the Novak mentality that I had against him at the Olympics as well."

Zverev has a 4-0 record against final opponent Rublev but he was wary of his opponent.

"Favourite or not, I think if you're in the final, there's no easy opponent," he said. "Today he played incredible beating Medvedev."

Nick Kyrgios, John Isner and Reilly Opelka have been named by Team World captain John McEnroe as his final three picks for the Laver Cup.

The trio join Denis Shapovalov, Felix Auger-Aliassime and Diego Schwartzman for the team event which runs from September 24-26 at TD Garden in Boston.

Laver Cup newcomer Opelka rose to a career-high world number 23 ranking en route to his first ATP Masters 1000 final in Toronto and defeated world number three Stefanos Tsitsipas, who will play for Bjorn Borg's Team Europe.

Isner, who has featured for Team World since the inaugural event in 2017, reached the semi-finals in Toronto and claimed his 16th ATP Tour title in Atlanta at the start of August.

He described the Laver Cup as "a highlight of my year", adding: "To be on a team with guys we're normally competing against is so different and so much fun. We come together so well as a group, the chemistry is awesome and it's such a great environment to be part of."

Australian firebrand Kyrgios is a striking inclusion in Team World's roster, while Team Europe will be without their big three: Roger Federer, Rafael Nadal and Novak Djokovic.

Federer and Dominic Thiem were expected to take part in this year's event, though both were forced to withdraw with injuries.

However, Borg's men still boast six of the world's top 11. World number two Daniil Medvedev leads the line-up, with Tsitsipas and Tokyo Olympics gold medallist Alexander Zverev for company.

Casper Ruud, who collected a 14th win in his last 15 completed matches on tour when he beat Opelka on Wednesday, will feature, while Andrey Rublev and Wimbledon finalist Matteo Berrettini complete the six-man team.

Team Europe have landed the title in each of the three editions of the tournament so far, with Prague, Chicago and Geneva having served as hosts.

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."

Selemon Barega took the first athletics gold of the Tokyo 2020 Olympics on a day when Novak Djokovic saw his Golden Slam hopes ended.

Barega topped the podium for Ethiopia as he saw off competition from Ugandan duo Joshua Cheptegei and Jacob Kiplimo on Friday.

The 21-year-old ran a smart race and had the stronger finish in him to see off pre-race favourite Cheptegei, who took silver ahead of compatriot Kiplimo.

"It means a lot to me because I have been practising a lot, not only by myself but together with the Ethiopian people," said Barega, who quickly sets his sights on future success.

"As an athlete the primary target for us is to participate in the Olympics, be a champion, and also be able to break the record.

"So I'm really thinking about future opportunities for me to achieve that, and if possible I'm also communicating with my manager about that."

There was no such joy for Djokovic as his bid to become the first man to win a calendar Golden Slam was crushed by a semi-final defeat to Alexander Zverev.

Djokovic was a set and a break up but the Serbian contrived to lose eight games in a row en route to a 1-6 6-3 6-1 loss.

Germany's Zverev had sympathy for his beaten opponent, who he declared as the greatest of all time.

He said: "I know that he was chasing history, chasing the Golden Slam and chasing the Olympics, but in these kind of moments me and Novak are very close. Of course I'm happy that I've won, but at the end of the day I know how Novak feels.

"I feel sorry for Novak, but he's won 20 grand slams, 550 Masters Series or whatever, you can't have everything.

"He's the greatest player of all time, he will win the most grand slams out of anybody on tour, but I'm also happy that I'm in the final."

Defeat in the mixed doubles means the 20-time grand slam champion will face two bronze medal matches in Japan.

MIXED RELAY WOES FOR USA

The 4x400 metre relay mixed event made its debut in the Olympics on Friday but it did not go well for the favourites as the United States suffered disqualification.

One of the team's baton exchanges was deemed to have taken place outside the designated zone, ending their campaign and leaving the gold medal up for grabs.

Poland qualified fastest with a time of three minutes 10.44 seconds, with the Netherlands close behind and Jamaica also in the mix.

SCHAUFFELE LEADS THE WAY IN RAIN-AFFECTED MEN'S GOLF

Xander Schauffele fired a 63 to move top of the leaderboard at Tokyo 2020, while home favourite Hideki Matsuyama and Rory McIlroy made big moves on Friday.

The threat of serious weather caused another delay on day two, and eventually brought an early end to play with Matsuyama among those not to finish his round.

But Schauffele, who has a big following in Japan as his mother was brought up in the country, sat pretty at 11 under as the stellar names bared their teeth at Kasumigaseki Country Club.

Matsuyama was six under through 16 holes of his second round and eight under overall for the tournament.

McIlroy matched Matsuyama's round-one score but shot five under in round two and is well in the mix four shots back.

A LONG TIME COMING

Ma Long took gold in the table tennis as he became the first man to win consecutive Olympics titles in the event.

It was an all-Chinese final and Ma roared to victory against Fan Zhendong.

China also secured a one-two in the badminton mixed doubles.

IGLESIAS CAN BE CUBA'S HERO

Cuban welterweight fighter Roniel Iglesias earned a third Olympic medal after sinking American Delante Johnson with a sweep of the scorecards.

After a bronze in Beijing and gold at London in 2012, Iglesias savoured another chance to target the top step of the podium.

The 32-year-old said: "It is my third medal which is very important but what I really want is to win the gold medal. It is a historic moment for me and for my country, Cuba. I am very happy at this achievement."

Light heavyweight Ben Whittaker admitted he was a blubbering mess after securing at least a bronze medal for Great Britain. He set up a semi-final against Imam Khataev – representing the Russian Olympic Committee – after scoring a majority points win over Brazilian Keno Machado.

Whittaker was overwhelmed by the result and burst into tears at the realisation he would be taking home a medal.

"That was the hard part, getting that medal," Whittaker said. "I won't relax, but I've pushed through that first door now and all I have to do is start changing that colour. Bronze is a lovely colour but everyone wants gold."

DRAMA APLENTY IN WOMEN'S FOOTBALL

The quarter-finals of the women's football competition delivered on drama in a big way.

Penalty shoot-outs were needed for Canada and the United States to progress to a last-four showdown, with Brazil and the Netherlands their respective victims.

Australia won a seven-goal thriller 4-3 against Great Britain after extra time and will now meet Sweden, who knocked out hosts Japan 3-1.

Alexander Zverev apologised to Novak Djokovic after ending the Serbian superstar's hopes of a glorious Golden Slam – but joked it was about time someone else landed a major tennis title.

In their Olympic Games semi-final, it seemed Djokovic was cruising through to the gold medal match when he surged a set and a break of serve ahead.

Incredibly, though, Zverev won 10 of 11 games from 3-2 behind in the second set to take the match 1-6 6-3 6-1 and set up a shot at Karen Khachanov in Sunday's final.

Djokovic swept to Australian Open, French Open and Wimbledon trophy success before heading to Japan for the Olympics, the fourth leg of a potential sweep of each of the year's majors and the Tokyo 2020 singles title.

He had spoken of it becoming closer to a reality, as he attempted to match Steffi Graf's achievement from 1988, when she followed triumphs at each of the slams by winning in the October 1 final at the Olympics, held in Seoul that year. Graf remains the only player to have pulled off the feat in the same year.

Zverev had other ideas, but he also had sympathy for Djokovic when they exchanged words at the net.

"I told him that he's the greatest of all time, and he will be," Zverev said.

"I know that he was chasing history, chasing the Golden Slam and chasing the Olympics, but in these kind of moments me and Novak are very close. Of course I'm happy that I've won, but at the end of the day I know how Novak feels.

"I feel sorry for Novak, but he's won 20 grand slams, 550 Masters Series or whatever, you can't have everything.

"He's the greatest player of all time, he will win the most grand slams out of anybody on tour, but I'm also happy that I'm in the final."

Victory at Wimbledon earlier in July took 34-year-old Djokovic to 20 grand slam titles, level with Roger Federer and Rafael Nadal for the most by a man in the history of tennis, and Zverev was lurching towards becoming his latest victim when their Tokyo tussle began in a one-sided manner.

"I was down a set and a break, so I needed to change something. I started playing much more aggressive," Zverev said. "I started to swing through the ball a little bit more, and I tried to dominate that way."

Zverev is assured of at least a silver medal now, while Djokovic faces a bronze medal play-off against Spain's Pablo Carreno Busta.

"It's an amazing feeling knowing that you're going to bring the medal back to your house, back home to Germany," Zverev said.

"It's incredible beating the best player in the world undoubtedly right now and in this season. It seemed it was impossible to beat him at this event, so I’m very happy right now. But yet there's still one match to go."