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."

Novak Djokovic moved within two wins of an historic calendar Grand Slam at the US Open after completing a merciless comeback against Matteo Berrettini 5-7 6-2 6-2 6-3 en route to the semi-finals.

Berrettini was seeking revenge for his Wimbledon final loss to Djokovic and the Italian sixth seed gave himself a good chance after winning the opening set at Flushing Meadows on Wednesday.

But Berrettini was helplessly outclassed in a devastating display from world number one Djokovic, who is bidding to become just the third man to sweep all four majors in a year and first since 1969.

The 20-time major champion, who can also break the record for most men's slam titles – currently tied with Rafael Nadal and Roger Federer, will face Alexander Zverev in the New York semis.

For the third consecutive match, Djokovic done it the hard way, rallying after dropping the opening set, just like he did against Jenson Brooksby and Kei Nishikori.

In a brutal display of big hitting, Berrettini had the crowd roaring – firing down seven aces and saving two break points in a marathon first set lasting one hour, 17 minutes.

Berrettini held serve in a physically demanding sixth game after 12 minutes and seven deuces.

Djokovic – not without his chances – did not look like his usual self, spraying a forehand wide as Berrettini seized control following four set points.

Berrettini was looking to claim his first win over Djokovic after three consecutive defeats and earn his first top-10 victory at a grand slam (0-5 heading into the contest), but the Serb star turned the match on its head into the second set.

Djokovic, though, flipped the switch as he broke for the first time to move 3-1 ahead before consolidating for a 4-1 lead, silencing the pro-Berrettini crowd in New York, where the latter was unable to stop the rot.

Berrettini looked deflated and tired in the third set – Djokovic racing out to a commanding 3-0 advantage.

Djokovic missed the chance to move 5-2 ahead but it only delayed the inevitable as he fended off a break point the very next game to eventually earn a two-sets-to-one lead.

And the 34-year-old could not be stopped as he celebrated his 80th US Open match win in emphatic fashion.

Data slam: Can Djokovic be stopped?

Djokovic extended his winning streak at grand slams to 26 matches, while he also remains unbeaten in US Open quarter-finals (12-0). The record-chasing star also owns a 9-0 major record in 2021 after dropping the first set.

WINNERS/UNFORCED ERRORS

Djokovic – 44/28
Berrettini – 42/43

ACES/DOUBLE FAULTS

Djokovic – 12/4
Berrettini – 17/2

BREAK POINTS WON

Djokovic – 5/16
Berrettini – 1/5

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."

Second seed Daniil Medvedev refuses to start thinking about a US Open final against Novak Djokovic despite reaching his third straight semi-final at Flushing Meadows on Tuesday.

Medvedev dropped a set for the first time at this year's US Open but still got through, winning 6-3 6-0 4-6 7-5 over Dutch qualifier Botic van de Zandschulp on Tuesday.

The 25-year-old will play the winner of the quarter-final between Canadian 12th seed Felix Auger-Aliassime and Spanish teenager Carlos Alcaraz in the last four.

Top seed Djokovic, who has won all three majors this year, looms on the other side of the draw, with a quarter-final match-up on Wednesday against sixth seed Matteo Berrettini, while fourth seed Alexander Zverev is still alive.

"I don't think about him [Djokovic], because as we saw, anybody can beat anybody," Medvedev said at his post-match news conference.

"If he's in the final, and if I'm there, I'm happy. He plays on the days where I don't play so I watch his matches just because I enjoy watching tennis.

"I'm not going to root or cheer for somebody. I'm just gonna enjoy the tennis and then prepare for the winner. It's same every match."

Medvedev's victory clinches his spot in the final four at Flushing Meadows for the third straight year, having lost the 2019 final to Rafael Nadal.

"[I'm] really happy to be in the semis again, third time in a row," Medvedev said. "I couldn't dream of it four years ago, but now it's three."

Medvedev will be several years older than his next opponent, with Auger-Aliassime turning 21 last month and Alcaraz is still only 18.

Neither has ever reached a major semi-final either, while Medvedev will be playing in his fourth, having won two of them previously including at this year's Australian Open.

"I always said that experience helps me," Medvedev said. "You never know, because you're gonna play tough opponents, semis or final.

"Who knows? Maybe Novak. But first of course Felix or Carlos. Whoever wins gonna be on huge fire. You know they are much younger than even me.

"But for them it's going to be a first semis of a slam. Experience is not everything, because, for example, when I was in my first semis of a slam, I won it. Doesn't mean if you're there for the first time you're gonna lose it. But I like that I have this experience."

Jenson Brooksby has confidence he can compete with anybody after threatening a fourth-round upset against Novak Djokovic at the US Open.

The unheralded American posed a real problem for Djokovic at Arthur Ashe Stadium and took out the opening set 6-1 in New York City.

It was not to be, though, as Djokovic – chasing a calendar Grand Slam – roared back to win 1-6 6-3 6-2 6-2.

Despite falling short, Brooksby is only looking at the positives from going toe-to-toe with the world number one in such a huge match.

"It's definitely all positive things to take away. I learned my game. I'm feeling really confident in my game. I believe I can compete with anybody," Brooksby said after his first run to the second week of a grand slam.

"I knew it would be important to start strong, to impose my mindset and my strategy, my game out there. It's definitely special. I mean, I always enjoy the matches and everything throughout the moment. Obviously you have to stay focused.

"Afterwards, you can always have time to reflect more. Just appreciate and enjoy for the whole journey.

"Atmospheres like that are what you want to be in front of since you were a little kid, watching on TV when you were young, and now you're living it. It is something I really appreciate and I'm grateful to be here now. I'm excited to keep [playing] in atmospheres like this for the future."

Brooksby required treatment a couple of times during the match and revealed he was contending with an issue to his left hip.

"Yeah, there was something. Something that kind of came up from later in the second match, then in the third one. Even with a day off, then kind of into today, like my left hip kind of was bothering me even early on and more into it," he added.

"Not like it's an excuse or anything, but it kind of went throughout the leg today a bit. I was struggling more to push off and move. But that's part of the sport. I did everything I could to feel the best I can going out there today and all the other days. There's no regrets on that.

"I definitely think if there wasn't that, I could have kept a better level up closer to the first set throughout the rest of the match."

Brooksby only reached the world's top 100 earlier this month and is now projected to be on the cusp of the top 40.

The 20-year-old relished his first experience of playing on Arthur Ashe.

"I did take time to look around a little bit, just appreciated being in an atmosphere like that with so many people cheering you on. Took a moment to still have it all in after," he said. 

"You're not going to win every match you play obviously, but you still have to enjoy it.

"I think [the belief] comes from definitely more training, but most importantly other match situations against other guys and just the whole process of it. 

"Leading up to it, I 100 per cent believed I could win against anybody. I thought I showed that with the level I could produce out there. Unfortunately, physically it got a little tougher."

Novak Djokovic said "I'll take your legs out, that's for sure" after digging deep to outlast American qualifier Jenson Brooksby in a physically demanding encounter at the US Open.

Djokovic – bidding to become only the third man to claim a calendar Grand Slam and first since Rod Laver in 1969 – rallied from a set down to prevail 1-6 6-3 6-2 6-2 en route to the quarter-finals in New York on Monday.

It was a brutal clash on Arthur Ashe Stadium, 20-time major champion and top seed Djokovic needed almost three hours to see off world number 99 Brooksby, who was making his debut at the iconic venue.

After being blitzed in a 29-minute opening set, Djokovic and Brooksby contested a gruelling 20-minute fifth game in the second set – the latter converting a sixth break-point chance.

Djokovic's physical superiority, however, was on display as the Serb star eventually powered past the spirited 20-year-old at Flushing Meadows.

During the last-16 matchup, former world number one Andy Roddick tweeted, in reference to Djokovic, "first he takes your legs… then he takes your soul".

Djokovic – who will face sixth seed Matteo Berrettini in a repeat of the Wimbledon final – said on court: "Thanks Andy, I take that as a compliment – only the first part.

"The second part, I don't take anybody's soul. Everyone has their soul, we're all beautiful souls so I appreciate everyone. But I'll take your legs out, that's for sure."

Djokovic hit 44 winners in the four-set triumph, to go with 41 unforced errors in a tricky clash under the Arthur Ashe lights.

With his hard-fought victory, Djokovic improved to 11-0 against Americans at the US Open. He is 29-3 at major events and 70-10 in ATP Tour-level matches.

The 34-year-old is on a 21-match winning streak against players from the United States since Sam Querrey snapped his 30-match slam streak at Wimbledon in 2016.

"Great quality match," Djokovic, who can break the record for most men's slam titles – currently level with injured pair Rafael Nadal and Roger Federer, told reporters. "He started off better. I've never played him. I didn't see him play too many times. Maybe few matches in the last few months. Haven't followed his career prior to that, so I didn't know much about him. Had to do some homework and some analysis.

"It's different stepping out on the court first time against someone that really has nothing to lose. He's a young, talented player that is very crafty. He's got the really all-around game. He was pumped. He had the crowd behind him, of course. He played a perfect first set. Everything he intended to do he executed it perfectly.

"On my end, I was just trying to find a rhythm, trying to read his game, trying to understand where I can find holes in his game and start to attack and shift the momentum to my side.

"That happened already at the beginning of the second set. I broke him early. He broke back. But I re-broke his serve right away. We had some very, very long rallies, long games. It took a toll physically I think on both of us at that point. But I managed to find the right serves. I served efficiently when I needed to, opening up the court.

"The third and fourth set were really, really good from my side. I felt I was more dominant. I decreased the unforced errors that were really high in the first part of the match. I just was kind of swinging through the ball better. Was a good finish. It wasn't a good start. But all in all, expected the battle, and I got that one. I'm pleased to overcome it."

World number one Novak Djokovic's quest for a calendar Grand Slam and record-breaking 21st major title remains on track after outlasting Jenson Brooksby 1-6 6-3 6-2 6-2 in a gruelling US Open showdown.

Unheralded American qualifier and world number 99 Brooksby had the crowd roaring following an incredible opening set against Djokovic in Monday's last-16 clash at Flushing Meadows.

However, Djokovic – bidding to become only the third man to sweep all four slams in the same year and first since Rod Laver in 1969 – responded to the almighty challenge, showcasing his superior physicality as the three-time US Open champion rallied into the quarter-finals in New York.

Brooksby was making his first appearance on Arthur Ashe Stadium, where the 20-year-old was looking to become the lowest-ranked player to beat a number one at the US Open since the start of the ATP rankings in 1973 and youngest American man since Andy Roddick (2003 Wimbledon) to reach a major quarter-final.

He was not overawed on the big stage, blitzing Djokovic in a remarkable first set. Playing with a bounce in his step and bringing the crowd to its feet, Brooksby only hit one unforced error in a dominant 29-minute display, which included two breaks of serve.

Djokovic was 38-34 at grand slams when losing the opening set and 12-10 at Flushing Meadows and after an error-filled opener, the Serb star let out an almighty roar after racing out to a 3-0 lead.

Just as Djokovic – level on 20 men's slams with Rafael Nadal and Roger Federer – looked comfortable, he endured a marathon 20-minute fifth game against Brooksby.

Brooksby broke at the sixth time of asking and the breath-taking tennis continued as Djokovic broke straight back to reclaim his advantage at 4-2 – the latter ending the game with an intense stare down in the direction of his opponent.

After a gruelling second set to level the match, the third followed a similar pattern, with Djokovic breaking in the opening game before moving 3-0 ahead.

Djokovic did not relinquish that lead, hitting 13 winners while claiming 11 of his 13 points at the net as he took the match to Brooksby.

Brooksby put up a huge fight but, he was unable to maintain his charge as the crowd went silent – Djokovic looking ahead to a last-eight showdown with sixth seed Matteo Berrettini in a rematch of the Wimbledon final.

Data slam: Djokovic flawless against locals in New York

With his hard-fought victory, which lasted almost three hours, Djokovic improved to 11-0 against Americans at the US Open. He is 29-3 at major events and 70-10 in ATP Tour-level matches. The 34-year-old is on a 21-match winning streak against players from the United States since Sam Querrey snapped his 30-match slam streak at Wimbledon in 2016.

WINNERS/UNFORCED ERRORS

Djokovic – 44/41
Brooksby – 27/28

ACES/DOUBLE FAULTS

Djokovic – 9/1
Brooksby – 4/1

BREAK POINTS WON

Djokovic – 6/12
Brooksby – 3/11

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."

Novak Djokovic powered through to week two of the US Open by sinking Kei Nishikori, a player who must be sick of the sight of the Serbian.

For a 17th consecutive time in their rivalry, Djokovic beat the former world number four, who was runner-up at this tournament seven years ago.

A 6-7 (4-7) 6-3 6-3 6-2 victory in three hours and 33 minutes for Djokovic moves him into the fourth round, ever closer to the calendar Grand Slam he is chasing, having already won the Australian Open, French Open and Wimbledon.

Nishikori beat Djokovic in the US Open semi-finals in 2014, before losing to Marin Cilic in the final, but that was the last time he got the better of the man from Belgrade.

Djokovic won their 2018 semi-final at Flushing Meadows for the loss of just nine games and a 6-2 6-0 win for the world number one over Japan's Nishikori at the Tokyo Olympics in July suggested this latest clash in New York, the 20th between them, could be similarly one-sided.

Yet it became clear early in this clash that Djokovic faced a substantial test. He trailed 4-2 in the opener and could not save the set, despite forcing a tie-break. A stunning lob from Nishikori gave him two serves for the set, and he held his nerve to move in front.

Djokovic broke in the third game of the second set though and staved off a flurry of break-back points on his way to levelling the match.

When Nishikori served a double fault to allow Djokovic two break points in game four of the third set, it was inviting trouble. Djokovic won the second of those when his low slice and net rush prompted Nishikori to net a backhand.

Against the flow of the match, Nishikori broke back, helped by two consecutive double faults, but order was restored as Djokovic rolled through the next two games to move a set away from the next round.

Nishikori probably needed Djokovic's body to fail him, or for something as bizarre as last year's disqualification to occur, but nothing of the sort happened in set four, the world's best player in a class of his own.

Djokovic said: "I don't think I started off very well. I was too passive and too far back in the court and he was dictating the play. It took me a little bit of time to adjust to his game.

"By the beginning of the second set I felt like I was getting my groove back, getting my rhythm back. I was very pleased with my focus."

DATA SLAM

Nishikori will look back to the second set and ponder 'what if?', because he had seven break points and took none of them. Djokovic had three in that set and took two, and there lies greatness. Tennis comes down to taking chances as they arrive, being clinical, and after the chaos of the first set this was a ruthless Djokovic show.

WINNERS/UNFORCED ERRORS

Djokovic – 45/52
Nishikori – 38/56

ACES/DOUBLE FAULTS

Djokovic – 15/7
Nishikori – 6/3

BREAK POINTS WON

Djokovic – 7/16
Nishikori – 2/13

Novak Djokovic says he was not acting like a "spoiled brat" when he complained about a rowdy spectator during his US Open defeat of Tallon Griekspoor.

World number one Djokovic took another stride towards a first calendar Grand Slam and a record 21st major title by beating Dutchman Griekspoor 6-2 6-3 6-2 in the second round on Thursday.

Top seed Djokovic, who will face Kei Nishikori in the third round, had to contend with a member of the crowd trying to unsettle him in Arthur Ashe Stadium.

He shouted as the Serb went for an overhead smash that he missed and continued to be vocal during points, prompting Djokovic to express his grievances with the chair umpire.

Djokovic feels it is important to make it clear that sort of behaviour should not be tolerated.

"When tennis players talk about that, someone who is watching team sports would say, 'What a spoiled brat'," the three-time US Open champion said.

"But it's a different sport. Look, there's a lot of noise happening on the stadium, particularly in the night sessions. I don't mind that.

"Even sometimes during the point it happens that people out of excitement, they just scream, or they release like a sound or whatever, sigh, whatever you call it. And that's fine.

"But if someone intentionally does it over and over again, then I have tolerance up to a certain point, then it's not correct, then it's not fine. It's not fair. I feel like it's not good for us players.

"I mean, particularly that guy for some reason was calling, raising the sound and kind of screaming just before I would hit my smash, which was a big point. Before that he would do [it] a few times. After that again.

"That wasn't nice. That's all. I don't mind the noise. Don't get me wrong. I think it's important for the entertainment, for the crowds, the music.

"I get it. But if someone does it over and over again, particularly when you are at his side, he knows why he's doing it. The guy that I pointed out, he knew exactly what he was doing, and that's all."

Novak Djokovic welcomed the ongoing 'GOAT' discussion alongside Rafael Nadal and Roger Federer after the world number one took another step towards an historic grand slam title at the US Open.

Djokovic, Nadal and Federer share the most men's slams in history with 20 but the former has the chance to break the record at Flushing Meadows, where the top seed dismantled unheralded Dutchman Tallon Griekspoor 6-2 6-3 6-2 in the second round on Thursday.

Serb star Djokovic is also bidding to become just the third man to complete a calendar Grand Slam and the first to sweep all four majors in a year since Rod Laver in 1969.

It is widely debated who is the greatest player of all time among Djokovic, Nadal and Federer – the latter two are both absent from this year's US Open due to injury.

After reaching the third round in New York, Djokovic was asked who the better player on a neutral surface is, given Nadal's clay-court dominance and Federer's grass-court expertise.

"It's difficult to say who is better. Three of us, we're all so different. We have different styles," Djokovic said during his post-match news conference.

"We have different trajectories or journeys to where we are at this moment. We all had tremendous success, some more particularly on one surface, some the other surface.

"We do complement each other. I think the rivalry between the big three, so to say, it's phenomenal for our sport.

"So the more traction, the more conversation there is around the three of us, the GOAT discussion, et cetera, the better in general for our sport. I hope people still keep on talking about it."

Djokovic added: "I think actually one of the best I think images that I've ever seen from tennis is them [Nadal and Federer] playing on a half-grass, half-clay court.

"I thought that was fantastic. Whoever came up with the idea was genius. As a tennis fan, I enjoyed that very much."

Djokovic hit 33 winners, fired down 13 aces and broke six times throughout a dominant performance against Griekspoor under the Arthur Ashe Stadium lights.

The 34-year-old also improved to 53-1 against non-top 100 opponents at majors, while he is now 13-0 against them at the US Open.

Kei Nishikori awaits Djokovic, who owns a 17-2 head-to-head record against the 2014 US Open runner-up.

"We played many times. I have very good score against him," Djokovic said of Nishikori. "I lost I think last time here in New York in semis in 2014. Historically I think his most successful grand slam is here. He's one of the quickest and most-talented players that I've seen in my lifetime, in my career.

"I think it's important for me to serve well and try to take off the pace a little bit because he likes the pace. He likes to hit the ball early, protect the line. But I know his game well. We played in Olympic Games. I know what's expecting me. I look forward to a good challenge."

History-chasing world number one Novak Djokovic cruised through to the third round of the US Open at the expense of Tallon Griekspoor 6-2 6-3 6-2.

Djokovic is bidding to become just the third man to complete a calendar Grand Slam and the first to sweep all four majors in a year since Rod Laver in 1969.

The top seed, who is also pursuing a record-breaking 21st slam crown – currently level with injured stars Rafael Nadal and Roger Federer on 20 – outclassed Griekspoor in one hour, 39 minutes on Thursday.

Awaiting Djokovic is 2014 US Open finalist and Japanese star Kei Nishikori in the third round.

Djokovic, who withstood a spirited challenge from Holger Rune in the opening round before the teenager succumbed to cramps, asserted his dominance against Griekspoor from the outset on Arthur Ashe Stadium.

Boasting a 14-0 record in second-round matches at the US Open, Djokovic only lost one point on his first serve in the opening set and fired down five aces, while hitting 13 winners and converting two of his three break points.

While world number 121 Griekspoor managed to break Djokovic's serve in the second set, the Serb was typically efficient as he builds towards another shot at history in New York.

Coming to the net more in the third set, Djokovic was determined to get off the court as quickly as possible and he did just that – saving three break points en route to another third-round appearance at the year's final slam.

Data slam: Djokovic continues strong record

The 34-year-old came into the contest with a 52-1 slam record against non-top 100 opponents. Djokovic improved to 53-1 – his lone loss to world number 117 Denis Istomin at the 2017 Australian Open – and a perfect 13-0 at the US Open with his straight-sets victory.

WINNERS/UNFORCED ERRORS

Djokovic – 33/20
Griekspoor – 20/28

ACES/DOUBLE FAULTS

Djokovic – 13/5 
Griekspoor – 5/2

BREAK POINTS WON

Djokovic – 6/10
Griekspoor – 1/4