Andy Murray put his body to the test as the former world number one overcame teenage sensation Carlos Alcaraz at the Indian Wells Masters, where stars Stefanos Tsitsipas and Alexander Zverev advanced to the third round.

Murray needed more than three hours to see off 18-year-old talent Alcaraz, who announced himself on the big stage with a quarter-final run at the US Open.

An Indian Wells runner-up in 2009, Murray was joined in the next round by second seed Tsitsipas and third seed Zverev on Sunday.

MURRAY WINS BATTLE OF GENERATIONS

Injuries have struck down Murray in recent years, but the three-time grand slam champion showed there is still plenty of fight left in the tank after rallying past debutant Alcaraz 5-7 6-3 6-2.

Facing a player 16 years his junior, Murray – making his 13th Indian Wells appearance – reached the third round of an ATP Masters 1000 event for the first time since 2016.

The 34-year-old Murray, who hit an underarm ace, improved his record to 27-12 in the desert following three hours, four minutes on court.

"He's obviously got so much potential, so much firepower and these conditions it's not easy to finish points off quickly, but he's able to because he has so much pace from the back of the court so I had to fight extremely hard, coming back from a set down," said Murray, who will next meet Zverev. 

"I felt like in the second set he played maybe better. First set I felt like I had more of the opportunities but didn't get it so yeah, happy with the way I fought. He's a top-drawer young player."

ZVEREV QUALIFIES FOR TURIN AS TSITSIPAS CRUISES

US Open finalist and Olympic gold medallist Zverev outlasted talented American Jenson Brooksby 6-4 3-6 6-1 to set up a showdown with Murray.

World number four Zverev ended the contest with 12 aces and 28 winners, having qualified for next month's ATP Finals in Turin thanks to the German's four tour-level titles in 2021.

"It wasn't an easy match, but I'm happy to be through, I'm happy to be in the third round and playing Andy now," said Zverev, who has won 18 of his last 19 matches since Wimbledon. "I think he's the only one of the 'Big Four' [including Novak Djokovic, Rafael Nadal and Roger Federer] I haven't beaten yet, so I hope I can change that. I think it's incredible how well he's moving and incredible how well he's playing. I think he's very motivated so I hope I can show my best tennis."

It was far more routine for Greek star Tsitsipas, who eased past Pedro Martinez 6-2 6-4 in his tournament opener.

Tsitsipas needed just 93 minutes to take down his opponent for his Tour-leading 52nd win of the season as the French Open runner-up awaits 25th seed Fabio Fognini for a place in the fourth round.

BERRETTINI ROLLS ON AS AUGER-ALIASSIME SAYS GOODBYE

Italian fifth seed Matteo Berrettini won through to the third round via a 6-4 7-5 success against qualifier Alejandro Tabilo – his first Indian Wells win following two previous appearances.

Felix Auger-Aliassime was the biggest name to depart the event on Sunday, with the seventh seed and Flushing Meadows semi-finalist going down 6-4 6-2 to Albert Ramos-Vinolas.

Jannik Sinner, Pablo Carreno Busta, Cristian Garin and Gael Monfils were among the seeds to progress.

Domestic abuse allegations made against Alexander Zverev are being investigated by the Association of Tennis Professionals (ATP), the governing body has confirmed.

Zverev's former partner Olga Sharypova alleged in an interview last year that the German physically and emotionally abused her during a tournament in Shanghai in 2019.

World number four Zverev has strenuously denied the allegations.

After commissioning an Independent Safeguarding Report earlier this year, with the aim of ensuring all adults and minors involved in professional tennis are safe and protected from abuse, the ATP is now looking into the claims made by Sharypova.

A statement on Monday read: "The ATP fully condemns any form of violence or abuse and will investigate such allegations related to conduct at an ATP member tournament."

ATP chief executive Massimo Calvelli added: "The allegations raised against Alexander Zverev are serious and we have a responsibility to address them. 

"We hope our investigation will allow us to establish the facts and determine appropriate follow-up action. 

"We understand Zverev welcomes our investigation and acknowledge that he has denied all allegations. 

"We will also be monitoring any further legal developments following the preliminary injunction obtained by Zverev in the German Courts."

John McEnroe promised Team World would bounce back after suffering a 14-1 thrashing by Team Europe at the Laver Cup in Boston.

Europe wrapped up a fourth consecutive Laver Cup triumph as Andrey Rublev and Alexander Zverev capped off a dominant performance.

Having won all four matches on Saturday, Europe needed just one more victory to again retain the trophy, preserving their record of having won each edition of the tournament.

That duly arrived as Rublev and Zverev prevailed against Reilly Opelka and Denis Shapovalov in their doubles clash.

They emerged 6-2 6-7 (4-7) 10-3 victors, to spark European celebrations.

Next year's match will be played in London, and Team World captain McEnroe said: "No one wins the Laver Cup, beats us, John McEnroe, five times in a row. You've got to keep going.

"Team Europe is a great team, no question, incredible team. They had good team spirit. We did, as well."

McEnroe, quoted on the Laver Cup website, added: "If you get a couple of different results, we could have put more pressure on them. But we just came up short in four tiebreakers. You win half those, it's totally different story. We gave it our best, but they were just too good."

Zverev reflected on Europe's win, saying: "The score says that it was 14-1, but it could have gone both ways a lot of the time.

"We [did] a lot of hard work for this victory throughout the whole week. The group of this team has been absolutely amazing.

"I think a lot of us came a lot closer together and to be honest I can't wait for London next year."

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]."

Team Europe are on track for their fourth consecutive Laver Cup triumph after earning an early 3-1 lead against Team World.

Opening-day honours went to Bjorn Borg's Team Europe at TD Garden in Boston, where the defending champions moved into the box seat thanks to wins for Andrey Rublev, Matteo Berrettini and Casper Ruud in the singles on Friday.

John Isner and Denis Shapovalov managed to get Team World on the board in the evening's final doubles match against Alexander Zverev and Berrettini 4-6 7-6 (7-2) 10-1.

Roger Federer and Rod Laver were in the crowd as Team Europe – headlined by newly crowned US Open champion Daniil Medvedev and consisting of six of the world's top 10 – made a strong start courtesy of Norwegian Ruud, who overcame Reilly Opelka 6-3 7-6 (7-4), improving his career record to 3-0 against the towering American, and beating him in straight sets for the first time.

Italian star Berrettini then overcame Team World's Felix Auger-Aliassime 6-7 (3-7) 7-5 10-8 in the competition's longest match at two hours, 52 minutes.

Berrettini escaped with the second set after facing two break points in the penultimate game before prevailing against the Canadian in a thrilling match tie-break.

"One of the best matches bar none that I've ever seen played, absolutely just enthralling," said captain John McEnroe, whose Team World are eyeing their first Laver Cup trophy.

Rublev rallied past Argentina's Diego Schwartzman, who won the opening set and led 6-2 and 8-5 in the match tie-break before losing 4-6 6-3 11-9.

"Today we are a bit more lucky; Matteo won a tough match against Felix in a super tiebreak, now you saw my match," said Russian star Rublev.

"It was so close; Diego was leading all the super tiebreak, but in the end I find a way to win.

"This happens. This is tennis, this is sport. It’s emotions. Someone has to win, someone has to lose."

On day two, Stefanos Tsitsipas and Zverev headline the day session against Team World's Nick Kyrgios and Isner.

In the evening, Medvedev will meet Shapovalov before Rublev and Tsitsipas team up for a doubles battle with Kyrgios and Isner.

Novak Djokovic is well aware of the history he is poised to make in Sunday's US Open final, and he is not shying away from it. 

After his 4-6 6-2 6-4 4-6 6-2 defeat of Alexander Zverev in the semi-finals Friday, a win in the final against Daniil Medvedev would make Djokovic the first player since Rod Laver in 1969 to win all four majors in the same year.

It would also give him a record 21st grand slam title, breaking the mark he shares with Roger Federer and Rafael Nadal. 

Two astonishing achievements, neither of which is complete just yet, as Djokovic reminded observers by invoking a famous Kobe Bryant line. 

"Job is not done," Djokovic said. "Excitement is there. Motivation is there, without a doubt. Probably more than ever. But I have one more to go."

Djokovic did cross one statistical milestone off the list with Friday's win. He has now reached his 31st grand slam final, equalling Roger Federer's record. 

Since falling to Kei Nishikori in the last four at the 2014 US Open, Djokovic is 17-1 in grand slam semis. 

Zverev lauded Djokovic for his mental toughness as the world number one improved to 36-10 in five-set matches, but the top seed said he still has to fight himself to stay in control in high-pressure situations. 

"It's kind of a hurricane, a tornado, of emotions that you're going through in a sequence of one set or even one point," Djokovic said. "You are by yourself on the court, so there is no escape.

"You've got to find a way. And I think, over the years, I have managed to develop a formula that works for me. ...

"Tennis is a very beautiful sport but a very demanding sport and you've got to have mind and body balanced at all times if you want to compete at the highest level for the biggest trophies."

Few can match him on that stage and he will attempt to reach even greater heights with a win Sunday. 

His opponent, the second-seeded Medvedev, has dropped only one set on the way to the final. 

Djokovic beat him in straight sets in January to win the Australian Open and deny the 25-year-old Russian his first grand slam title. 

History will be on the line Sunday at Arthur Ashe Stadium, and Djokovic is embracing it. 

"There's only one match left. ... Let's do it,'' he said. "I'm going to put my heart and my soul and my body and my head into that one. I'm going to treat the next match like it is the last match of my career.''

To hear Alexander Zverev tell it, he would have needed to be perfect to beat Novak Djokovic in the US Open semi-finals. 

In the end, a wobbly beginning to the fifth set proved the German's undoing in a 4-6 6-2 6-4 4-6 6-2 defeat Friday simply because Djokovic was at his best when it mattered most. 

Combine that enduring quality with the Serbian's incredible statistical record, said Zverev, and you have the greatest player of all time.

Djokovic will have a chance to solidify that case Sunday when he faces Daniil Medvedev for the title. 

A victory would make the 34-year-old the first player since Rod Laver in 1969 to win all four majors in the same year and give him a record 21st grand slam title, breaking the mark he shares with Roger Federer and Rafael Nadal. 

"I think it's great for the sport," Zverev said after his loss. "Nobody thought anybody will do it again, what Rod Laver did. To see ]Djokovic] have the chance on Sunday, I do believe that he will do it is great. He's breaking every single record that there is.

"If you look at the stats, if you look the pure game of tennis action, he's the greatest of all time.

"Nobody is there with him, because most weeks world number one, most Masters 1000s titles, most likely going to be the most grand slams at the end of the day.

"And he has the chance of winning all four in the same year. How do you compete with that?"

Zverev certainly tried Friday, becoming the first player to push Djokovic to a fifth set since Stefanos Tsitsipas in the French Open final. 

"I fought back," he said. "I left it all out there. ... I mean, the match could have gone both ways, but it went his way. Very often it does."

On this night, Zverev said, it was largely Djokovic's serve on big points that boosted the top seed. 

Whatever shots happened to be working better than others for Djokovic, though, one factor stood above the rest, as it usually does for him at grand slams. 

"I think mentally he's the best player to ever play the game," Zverev said. "Mentally, in the most important moments, I would rather play against anybody else but him."

Novak Djokovic is one win away from becoming the first man to complete a Grand Slam in 52 years. 

The world number one fought back to defeat Alexander Zverev 4-6 6-2 6-4 4-6 6-2 Friday in the US Open semi-finals to put himself on the brink of history. 

Djokovic will face second seed Daniil Medvedev in Sunday's final as he attempts to win a record 21st grand slam title and become the first man since Rod Laver in 1969 to win all four majors in a calendar year. 

Laver was in attendance at Arthur Ashe Stadium to watch the top seed exert his will as he has done in so many five-setters over the years, breaking down the younger player over the course of the match to emerge with yet another triumph. 

Zverev had ended Djokovic's chances of a Golden Slam with a semi-final win at the Tokyo Olympics, rallying for a three-set win after dropping the opening set, but the script was different Friday. 

It started with Djokovic losing the opening set for the fourth successive match in New York. In the previous three rounds, he did not drop more than three games in any subsequent set, but Zverev made him work harder this time. 

With the first set even at 4-4, Djokovic fell behind 15-40 and double faulted on break point to give Zverev the opening he needed. Though his next service game was a bit shaky, Zverev managed to take the set when Djokovic mis-hit a forehand.

The German's momentum did not last, though, as he returned the favour by double faulting on break point in his first service game of the second set and watched Djokovic level the match with relative ease. 

Zverev had a chance to take control early in the third, earning two break points at 2-2, but he failed to convert and did not get another chance. When Djokovic had a similar opportunity up 5-4, though, he closed it out.

Down 0-40 in that game, Zverev saved two break points – the latter via an epic 53-shot rally that was the longest at this year's US Open – but Djokovic slammed home an overhead winner on the next point to take the set. 

Zverev shook off that disappointment and put the pressure back on Djokovic by hammering a forehand winner down the line to break the top seed and take a 2-1 lead in the fourth.

The German did not falter the rest of the set, eventually serving it out to force a decider and push Djokovic to a fifth set for the first time since the French Open final against Stefanos Tsitsipas. 

Djokovic jumped to an early lead in the fifth, forcing Zverev to the net on break point in the second game with a beautiful drop shot before finishing the younger player off with a cross-court winner. 

Djokovic reeled off four consecutive points to break Zverev in his next service game, then held at love to put the fourth seed on the brink at 5-0. 

Zverev, a winner in seven of his previous eight five-setters, did not surrender, breaking Djokovic thanks to a double fault on game point to pull within 5-2. 

But Djokovic ended it there, breaking back to close out the match in the next game as Zverev sent a forehand into the net from the baseline.

DATA SLAM

With the victory, Djokovic improved to 34-2 in night matches at Arthur Ashe Stadium and 36-10 in five-set matches in his career, winning his last seven in a row. 

WINNERS/UNFORCED ERRORS

Djokovic – 41/49
Zverev – 49/50

ACES/DOUBLE FAULTS

Djokovic – 12/2
Zverev – 16/8

BREAK POINTS WON

Djokovic – 5/8
Zverev – 3/12

Novak Djokovic knows he faces a tough challenge in his US Open semi-final with Alexander Zverev after coming from a set down to beat Matteo Berrettini.

The Serbian triumphed 5-7 6-2 6-2 6-3 to thwart Berrettini's revenge mission, having defeated the Italian in this year's Wimbledon final.

The world number one now faces the man who denied him a shot at the Golden Slam, with Zverev dumping Djokovic out of the semi-finals at Tokyo 2020.

And the 20-time grand slam winner was full of praise for his next opponent.

"He's in tremendous form, he's been winning a lot," said Djokovic, who still has the Calendar Grand Slam in his sights. "He has comfortably moved to the semi-finals here.

"I know his game well, we played in Tokyo. He's one of the best players in the world, but the bigger the challenge the more glory in overcoming it."

Reflecting on his victory over Berrettini, Djokovic felt he found his best form after dropping the opening set.

"This was a great match, with a lot of energy on and off the court," he said. 

"Matteo is a terrific player and every time we face each other it's a close battle.

"When I lost the first set, I managed to forget about it and move on. I was locked in at the start of the second and it was the best three sets I've played so far."

Alexander Zverev is riding a wave at the US Open after his confidence-boosting win over world number one Novak Djokovic en route to claiming gold at the Olympic Games.

Zverev survived a first-set scare to power past Lloyd Harris 7-6 (8-6) 6-3 6-4 in Wednesday's US Open quarter-final.

The German fourth seed will face either Djokovic, who is bidding to become just the third man to complete a calendar Grand Slam and first since 1969, or Matteo Berrettini for a spot in the men's final at Flushing Meadows.

Zverev – last year's US Open runner-up – said he has been fuelled by his semi-final win over Djokovic at the Tokyo Games.

"It's the biggest tournament in the world, Tokyo. It's the Olympics," Zverev said during his post-match news conference.

"Winning there against the world number one, especially that I was down a set and a break, being kind of out of the match, then coming back, it was different than the other matches. The emotions were different.

"Also securing a medal for Germany was very special to me. This year it seems like nobody can beat him in a big match, nobody can beat him at the grand slams.

"I feel like I was the first player to beat him in a very big match this year. That does give you something. To any person it would give you something.

"As I said before also, I think it was very important for me to back it up in the finals, back it up in Cincinnati. Hopefully I can continue this streak."

Zverev is in the midst of a career-best 16-match winning streak and has clinched 37 of 40 sets on the hard courts after winning Olympic gold and his fifth career ATP Masters 1000 crown in Cincinnati.

The 24-year-old is bidding to become the second man in history to win Olympic gold medal and the US Open/US Championships title in the same season, after Andy Murray in 2012.

On preparing against Djokovic, Zverev added: "You have to be perfect, otherwise you will not win.

"Most of the time you can't be perfect. That's why most of the time people lose to him. Against him, you have to win the match yourself. You have to be the one that is dominating the points. You have to do it with very little unforced errors.

"He is the best player in the world. He is very difficult to beat. But he's still also got to win tonight. He's playing Matteo Berrettini who is in very good form, finals of Wimbledon. I think he's looking forward to that match, as well. It's going to be an interesting match to watch those two."

Alexander Zverev won his 16th match in a row with a straight-sets victory over Lloyd Harris on Wednesday to reach the US Open semi-finals.

The fourth seed saved a set point from Harris in a tense opener and built on that to earn a 7-6 (8-6) 6-3 6-4 triumph in a little over two hours.

Zverev has dropped just one set across his five matches at Flushing Meadows this year and will face either Novak Djokovic or Matteo Berrettini as he seeks a place in back-to-back finals.

"I just hope their match goes on for eight hours and 30 minutes," Zverev joked when asked who he would prefer to face in the semi-finals.

"I didn't have a lot of chances on Harris' serve today and somehow managed to win that first set, which loosened me up a little bit and I started playing a lot better.

"In the third set, he started swinging. He started playing incredible tennis. So yeah, I'm happy to be through in three."

Harris beat three top-30 seeds to make it to this stage and more than held his own in the opening set against Zverev, who lost to Dominic Thiem in last year's final.

After sharing a break of serve apiece, Harris led 6-5 in the tie-break but lost the next three points to offer his opponent a platform to build from.

Despite struggling with a minor back problem, Zverev took advantage of his unseeded opponent's five unforced errors by holding throughout the second set.

The four-time grand slam semi-finalist raced into a 4-0 lead in the third set, but Harris slowly regained his composure and claimed the next three games.

Zverev's monster serve came to his rescue, however, as he took the eighth game and eased over the line in style with his 21st ace of the contest.

DATA SLAM

Zverev did not have things all his own way as he struggled in the opening set and was sloppy when leading 4-1 in the final set, but he ultimately proved too strong for an opponent ranked 46th in the world.

Last year's beaten finalist Zverev has served 83 aces and just 15 double faults across his first five matches and won 82 per cent of his first-serve points against Harris. Whether it is Djokovic or Berrettini, a tougher test awaits in the semi-finals.

WINNERS/UNFORCED ERRORS

Zverev – 43/26
Harris – 34/26

ACES/DOUBLE FAULTS

Zverev – 21/5
Harris – 13/1

BREAK POINTS WON

Zverev – 4/9
Harris – 2/3

Tokyo Olympic gold medalist Alexander Zverev refused to get carried away about his chances of winning his maiden major title despite easing into the US Open fourth round on Saturday.

The German fourth seed was leading 3-6 6-2 6-3 2-1 when Jack Sock withdrew with a groin issue which had been plaguing him throughout the match.

Zverev's walkover victory extended his winning run to 14 matches, dating back to his Tokyo 2020 gold medal triumph along with last month's Cincinnati Masters victory.

Reigning champion Dominic Thiem along with Rafael Nadal and Roger Federer all withdrew from the US Open prior to the tournament, opening the door for a first time winner.

"I’m on a 14-match winning streak now," Zverev said during his on-court interview. "I’m playing well. That’s all I want to say, I don’t want to say anything else.

"We all know that Novak is the big favourite, we all know that Daniil [Medvedev] is playing incredible tennis, we all know that there are a lot of other players out there that are playing incredible tennis.

"I think my fourth-round match against Jannik Sinner is going to be extremely entertaining because he’s a young guy that is very hungry and I feel like that’s going to be a high-level match."

Zverev also spoke about his drive to succeed at majors, having struggled earlier in his career.

The German was runner-up at last year's US Open and made the semi-finals at this year's French Open and last year's Australian Open.

Zverev's hopes for going deep at Flushing Meadows will be aided by the premature end to his match with Sock, having won in straight sets in the first two rounds over Sam Querrey and Albert Ramos Vinolas.

The Olympics gold medalist was full of praise for Sock, who has been plagued by injuries, after a dominant opening set.

"Jack I think played the best set of tennis I've ever seen him play," Zverev said. "I did one unforced error in the whole set and I lost it, 6-3, without having really any chances.

"If he would have kept it up I probably would not have won the match… Afterwards when he gets injured, it's a shame because otherwise it would have been an incredible match I think."

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."