Team Europe are poised to seal yet more Laver Cup glory after producing another dominant display against Team World, though the focus was on Nick Kyrgios following comments about his long-term future.

Europe swept Saturday's four matches in Boston to stand on the cusp of a fourth consecutive Laver Cup triumph – the defending champions lead 11-1 and require just two more points to clinch the title.

Stefanos Tsitsipas blitzed Team World's Kyrgios 6-3 6-4 at TD Garden, where Olympic Games gold medallist Alexander Zverev beat John Isner 7-6 (7-5) 6-7 (6-8) 10-5 before US Open champion Daniil Medvedev made light work of Denis Shapovalov 6-4 6-0.

Team Europe secured their fourth win of the day in the doubles – Tsitsipas and Andrey Rublev teaming up to defeat Isner and Kyrgios 6-7 (8-10) 6-3 10-4.

After Kyrgios' straight-sets loss to Greece's Tsitsipas, the 26-year-old Australian star casted doubt over his tennis future.

"This is my probably my last Laver Cup," former world number 13 Kyrgios – an Australian Open and Wimbledon quarter-finalist – told reporters post-match. "I don't know how much longer I will be in tennis.

"This is my last event of the year. I will get my body right ahead of the Australian Open.

"My mum is not doing too well with her health. I'd like to go back and see her."

"As long as I'm on the court, I will try and give my best, but I'm not going to lie and say that I'm going to plan to play four or five more years on tour," Kyrgios said. "That's just not me."

Playing for the first time since earning his maiden grand slam trophy at the expense of record-chasing Novak Djokovic at Flushing Meadows, world number two Medvedev suffered no letdown against Shapovalov.

"I played unbelievably, especially [in] the second set," Russia's Medvedev said in his on-court interview. "I didn't know what to expect because after the US Open, I didn't play for a week and a half. Came here, practised as much as I could the past three days, so I didn't hit [that] many balls, but was surprisingly feeling well.

"I wanted to show that also today. [The] first [set] was not easy, the ball was not going as fast as I wanted [and] he was playing really good. And then I just couldn't miss a ball anymore. I'm really happy about [that]."

Stefanos Tsitsipas plans to get the COVID-19 vaccine, having previously declared he would only do so if the ATP Tour made it mandatory.

Greek world number three Tsitsipas revealed last month he would not get a jab due to concerns over side effects.

The ATP Tour has persisted in encouraging players to get vaccinated, with Novak Djokovic the most high profile to have stated he was opposed to it, and Tsitsipas has now backtracked on his original stance.

"I will get vaccinated this year," the 23-year-old told Greek outlet Antenna TV. "So I can go to restaurants and shops. I support all those who get vaccinated.

"I am not a doctor; I am a tennis player, so I may not have the most substantiated opinion when it comes to medical issues."

The French Open runner-up was subject to backlash in his homeland following his initial comments on the vaccine, with a series of top figures questioning his thought process.

"The COVID-19 vaccine has not been tested enough because it is new and has some side effects," said Tsitsipas.

"I know some people who've had them. I'm not against it, I just see no reason for someone in my age group to be vaccinated [yet].

"For us young people I think it's good to pass the virus because we'll build immunity.

"I don't see it as something bad. As I said, it isn't obligatory, everyone has freedom to decide for themselves what's right and what's not. At some point we should all do it, I'm not saying the opposite.

"The time will come when we will not be given many options, but until then I want to see a better version of the vaccine that gives us more pluses than minuses."

Tsitsipas is set to play for Team Europe at the Laver Cup this week after missing Greece's Davis Cup tie with Lithuania due to a foot injury.

Carlos Alcaraz was lost for words after making history in the Spanish teenager's shock five-set upset of world number three Stefanos Tsitsipas at the US Open.

Alcaraz – rated by many as Spain's best young male player since 20-time grand slam champion Rafael Nadal first emerged – sent Tsitsipas packing 6-3 4-6 7-6 (7-2) 0-6 7-6 (7-5) in the third round on Friday.

The 18-year-old Alcaraz became the youngest player to reach the last 16 of the US Open since Americans Michael Chang and Pete Sampras in 1989.

Alcaraz also became the youngest man to beat a top-three opponent at the tournament since the ATP introduced its world ranking system in 1973.

After more than four hours on Arthur Ashe Stadium, Alcaraz told reporters: "I have not words to explain how I feeling right now.

"I just don't know what happened out there in the court. I can't believe that I beat Stefanos Tsitsipas in an epic match.

"For me it's a dream come true."

Amid comparisons with countryman Nadal, Alcaraz added: "Honestly I don't copy any style of a players. I just play my game.

"But if I have to say one player that is similar my game, I think it's [Roger] Federer. I think similar as mine game, trying to be aggressive all the time. I think it's a good similar for me."

After his US Open campaign came to a surprise end, third seed Tsitsipas tipped Alcaraz for future success.

"A hundred percent," Tsitsipas replied when asked if he had a sense of Alcaraz's potential. "I said he can be a contender for Grand Slam titles. He has the game to be there."

"I've never seen someone hit the ball so hard," French Open runner-up Tsitsipas added. "Took time to adjust. Took time to kind of develop my game around his game style.

"It's one of these matches and one of these feelings where, you know, you pick up at some point of the match, you feel like you're in control, and it doesn't really go your way at the end.

"It's kind of bitter, I would say, especially after such an incredible first set by my side, dominating, being just so aggressive, not dwelling on the past. It was a great first set.

"I don't know. I felt like he played the fifth one completely -- the way he played the first set basically, careless, going for every single shot. I have never seen someone play such a good fifth set, honestly."

Carlos Alcaraz put his name up in lights in New York as the 18-year-old stunned third seed Stefanos Tsitsipas in a massive US Open third-round upset.

Spanish teenager Alcaraz scored an astounding 6-3 4-6 7-6 (7-2) 0-6 7-6 (7-5) victory in a battle lasting four hours, seven minutes inside Arthur Ashe Stadium on Friday.

French Open runner-up Tsitsipas became the biggest casualty of the men's tournament so far as hot prospect Alcaraz showed his mettle on the grand slam stage at Flushing Meadows.

It means Alcaraz, rated by many as Spain's best young male player since Rafael Nadal first emerged, has reached the fourth round of a major for the first time in his career.

He becomes the youngest player to reach the last 16 of the US Open since Americans Michael Chang and Pete Sampras in 1989.

The US Open said the win made Alcaraz the youngest man to beat a top-three opponent at the tournament since the ATP introduced its world ranking system in 1973.

Alcaraz put a dire fourth set behind him and looked to have won the match with a lob at 6-4 in the deciding tie-break, but his ball landed a whisker long.

That meant the players were back on serve, but Alcaraz was unbowed and sealed victory with a scorching forehand winner, announcing himself as a likely superstar of the near future. He struck 61 winners in all.

He will face German qualifier Peter Gojowczyk in the fourth round, with a quarter-final place at stake.

Speaking on court after his win, Alcaraz hailed the supportive New York spectators who were firmly in his corner.

"I think without this crowd I haven't the possibility to win this match," he said. "Thank you to you the crowd for pushing me up in the fifth set

"It has been an incredible feeling for me. This victory means a lot to me. It's the best match of my career, the best win.

"For me to beat Stefanos Tsitsipas is a dream come true for me and to do it here is more special."

Men's tennis would be a safe environment for any gay player ready to announce their sexuality, three of the brightest young talents in the game have said.

Speaking on the US Open's first Pride Day, Stefanos Tsitsipas, Daniil Medvedev and Felix Auger-Aliassime said players should not fear coming out.

A number of the best-known women's players of all time have been lesbian, including Martina Navratilova, Billie Jean King and Amelie Mauresmo.

However, there have been few modern-era 'out' gay stars on the men's ATP Tour, with Navratilova having said in the past that those that exist have been "so far in the closet I don't know who they are".

Russian world number two Medvedev said: "From my side, I think everybody would be super open if somebody would come out on the ATP Tour.

"The other question is: are there any gays on the ATP Tour? Again, until somebody comes out, you cannot know unless you're his best friend and you know what he goes through.

"I think it's great from the US Open, this initiative. I think the ATP honestly is doing a good job, also especially internally trying to provide info and to just make sure that if anybody wants to come out, he's gonna feel safe and secure.

"All the players would be happy for the guy if he does it."

Canadian rising star Auger-Aliassime, who like Medvedev and Tsitsipas has reached round three at Flushing Meadows, explained it was important for the tour to let players be themselves.

On the women's tour, Belgian players Alison van Uytvanck and Greet Minnen are engaged, while there are a number of other players from the LGBTQ (lesbian, gay, bisexual, transgender, queer/questioning) community.

But the men's tour in recent years has seen no such prominently out players, which world number 15 Auger-Aliassime finds surprising, given the high number of professionals.

"Recently I've started doing a survey inside the ATP about the LGBTQ+ community," Auger-Aliassime said.

"It's important these days to be aware of that and to be open-minded and the ATP needs to do that, in today's time it's needed.

"The reason we don't have openly gay players on the ATP Tour, I'm not sure of the reason, but I feel me, as a player, it would be very open, very welcome. Statistically there should be some, but for now there's not."

Tsitsipas was asked whether the tour would be a "safe space" now, for any player considering coming out.

"I think so. They would be supported, for sure," said the Greek world number three, speaking on Wednesday's Pride Day in New York.

"I don't know how it is in other sports. I see no reason, for example, a tour like the ATP not to accept something like this."

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."

Andy Murray has doubled down on his criticism of Stefanos Tsitsipas by joking that his US Open conqueror's bathroom breaks take twice as long as Jeff Bezos' trips to space.

World number three Tsitsipas beat Murray 2-6 7-6 (9-7) 3-6 6-3 6-4 in a thrilling five-set battle in the opening round at Flushing Meadows on Monday.

The opening-day showdown was overshadowed by Tsitsipas' controversial bathroom break ahead of the decisive fifth set – the Greek star spending around eight minutes off court, much to the frustration of Murray.

Tsitsipas also required a medical timeout for an apparent foot problem after losing the third set to 2012 champion Murray, who was far from impressed following almost five hours of action.

Speaking after the match, Murray – who failed to progress beyond the first round of the US Open for the first time in 15 appearances – said he had lost respect for Tsitsipas and suggested his opponent had deliberately attempted to disrupt his flow. 

Tsitsipas defended his lengthy break, insisting he had played by the rules and that he would speak to Murray face-to-face should the Briton wish to take the issue further.

Rather than resolving the matter, however, Murray aimed another dig at Tsitsipas with a sarcastic message on his personal Twitter account on Tuesday, comparing the stoppage to the 10 minutes and 10 seconds it took billionaire Bezos to fly to space last month.

"Fact of the day. It takes Stefanos Tsitipas (sic) twice as long to go the bathroom as it takes Jeff Bazos (sic) to fly into space. Interesting," he posted.

With the win over Murray, Tsitsipas became the 10th active player to defeat all four members of the 'Big Four' – Murray, Novak Djokovic, Rafael Nadal and Roger Federer.

Tsitsipas will meet world number 44 Adrian Mannarino in the second round on Wednesday.

Andy Murray said he has lost respect for Stefanos Tsitsipas in a scathing criticism of the world number three's excessively long bathroom break at the US Open.

Tsitsipas rallied past three-time grand slam champion Murray 2-6 7-6 (9-7) 3-6 6-3 6-4 in a thrilling five-set battle in the opening round of the major at Flushing Meadows on Monday.

Murray's career has been devastated by injuries – the 34-year-old underwent hip resurfacing in 2019 but he has continued to be plagued by fitness problems – however he turned back the clock in a heroic display on Arthur Ashe Stadium, where the former world number one led two sets to one before Tsitsipas' comeback.

But the opening-day showdown was overshadowed by Tsitsipas' controversial bathroom break at the end of the fourth set – the Greek star spent around eight minutes off court, much to the frustration of Murray.

Tsitsipas also required a medical timeout for an apparent foot problem after losing the third set to 2012 champion Murray, who was far from impressed following almost five hours of action.

"It can't be a coincidence that it's happening at those moments. I don't believe it [Tsitsipas' foot] was causing him any issue at all," said world number 112 Murray after failing to progress beyond the first round of the US Open for the first time in 15 appearances.

"The match went on for another two-and-a-bit hours after that. He was fine, moving great I thought. It's just disappointing because I feel it influenced the outcome of the match. I'm not saying I necessarily win that match [without Tsitsipas' delays], for sure, but it had influence on what was happening after those breaks.

"I rate him a lot. I think he's a brilliant player. I think he's great for the game. But I have zero time for that stuff at all, and I lost respect for him."

"If people don't care enough about it to change, that's fine," Murray said of players taking long breaks.

"Look, I'll speak to my team about it. I'll listen to what, I don't know, fans, players and everything are saying about it. Maybe I'm being unreasonable. Maybe I'm overreacting to something because I lost the match.

"But yeah, right now sitting here I feel like it's nonsense and they need to make a change because it's not good for the sport, it's not good for TV, it's not good for fans. I don't think it's a good look for the players either.

"I'm sitting in here after a match like that against one of the best players in the world, and rather than talking about how fantastic he is, how good he is for the game, how great it was for me that I was able to put on a performance like that after everything that's gone on the last four years – I'm sitting in here talking about bathroom breaks and medical timeouts and delays in matches.

"That's rubbish, I don't think that that's right. I said I don't want to do press tonight because I know I'm going to sit here and it's going to seem like I'm just smashing him. Yeah, that's annoying for me because sounds like sour grapes because you've lost a match and everything.

"I would have said the same thing if I'd won, I promise. It was nonsense, and he knows it."

Stefanos Tsitsipas was able to breathe a sigh of relief on Arthur Ashe Stadium after the third seed rallied past former world number one Andy Murray 2-6 7-6 (9-7) 3-6 6-3 6-4 in a thrilling five-set battle.

French Open runner-up Tsitsipas and 2012 champion Murray was one of the standout matches in the opening round at Flushing Meadows and the near-five-hour showdown did not disappoint as the latter turned back the clock in New York on Monday.

Murray's career has been devastated by injuries – the 34-year-old underwent hip resurfacing in 2019 but he has continued to be plagued by fitness problems.

However Murray, who only had one pair of shoes, soaking wet with sweat, took a positive approach from the start and earned a surprise two-sets-to-one lead against the slam hopeful.

Murray, though, was made to rue his inability to capitalise on two set points at 6-4 in the second-set tie-break – leaving the door open for world number three Tsitsipas.

Tsitsipas held his nerve as the prospect of a first-round boilover beckoned, but it was not without controversy after the Greek star took his time in the bathroom between the fourth and fifth seeds, frustrating Murray.

It is the first time in 15 US Open appearances world number 112 Murray lost in the opening round in New York.

"It is not easy," Tsitsipas – who celebrated his ATP Tour-leading 49th victory of the year – said in his on-court interview. "I had to make lots of sacrifices to come back.

"I think the atmosphere was great today, with a lot of positive tennis. The New York crowd is known to be one of the best crowds in the world.

"The fact we are able to compete out here with an electric crowd today is something we have been waiting for."

Tsitsipas, who will meet Adrian Mannarino in the second round, added: "I hope I am able to keep my game at the same level as I managed today.

"Hopefully I will be back here on this court."

Stefanos Tsitsipas faces Andy Murray and Ash Barty will take on 2010 finalist Vera Zvonareva in the first round of the US Open.

French Open runner-up Tsitsipas and 2012 champion Murray is one of the standout matches in the opening round at Flushing Meadows.

Top seed Novak Djokovic will start his quest for a calendar Grand Slam against a qualifier in New York and could face a repeat of the Wimbledon final versus Matteo Berrettini in the last eight.

World number one Djokovic, a strong favourite for a record 21st major title with Rafael Nadal and Roger Federer absent due to injury, could do battle with Alexander Zverev at the semi-final stage.

Daniil Medvedev, the second seed, is in the bottom half with Tsitsipas, who he could come up against in the semi-final. Medvedev's first test will come against Frenchman Richard Gasquet.

Barty could come up against Iga Swiatek in the last eight and Karolina Pliskova if she makes it through to the semi-finals.

Simona Halep's encounter with Camila Giorgi is a mouthwatering first-round match, while defending champion Naomi Osaka returns to grand slam action against former US Open junior champion Marie Bouzkova.

Angelique Kerber could be a tough fourth round opponent for Osaka. Close friends Madison Keys and Sloane Stephens meet in another eye-catching first-round match.

There will be no Serena or Venus Williams at the final major of the year due to injuries.

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."