Defending champion Novak Djokovic reached the third round of the US Open on Wednesday as Laslo Djere retired in the third set, but said he’ll have to do better to win a fifth title on the hard courts of New York.

Djokovic was up 6-4, 6-4, 2-0 when Djere pulled the plug on a gritty encounter that saw both men summon the physio to Arthur Ashe Stadium.

“It’s not what we want to see,” Djokovic said. “He’s such a good player in these conditions and the second set should have been his, he was 4-2 up.

“I don’t know if (my) winning the second set probably put more burden on him.”

Djokovic notched his 90th US Open match victory, becoming the first man to win 90 at all four Grand Slams.

But it was a battle until the minute Djere called it quits.

Djokovic grabbed the first break of the match to take the first set 6-4 after a tense hour then sought treatment for trouble on his right side.

Djere, the only player to take a set off Djokovic at last year’s US Open, gained the first break of the second set and with a 4-2 lead had two more break points that he couldn’t convert.

But Djokovic won the next six games, Djere receiving treatment on his abdomen before Djokovic closed out the second.

The Serbian superstar, coming off an emotional Paris Olympics triumph, next faces Australian Alexei Popyrin, who he beat at the Australian Open and Wimbledon this year.

Women’s defending champion Coco Gauff overcame her own struggles on serve to beat 37-year-old Tatjana Maria 6-4, 6-0.

It was an uneven performance from 20-year-old Gauff, who has endured an erratic season since capturing her maiden major in New York.

She put just 44 percent of her first serves in play and had nine double faults, but the 99th-ranked Maria couldn’t capitalize and Gauff won the last seven games to seal the win.

Djokovic and Gauff missed the worst conditions of a steamy day that saw tournament organizers invoke the extreme weather rule allowing mid-match breaks.

Svitolina downs Kalinina: No.27 seed Elina Svitolina showed off the full range of her skills to go up a set and a break on Ukrainian compatriot Anhelina Kalinina in the US Open second round.

Svitolina went on to win 6-1, 6-2, her third win in as many meetings with Kalinina, to set up a marquee third-round clash with No.3 seed and defending champion Gauff.

Victoria Azarenka said she suffered a migraine during her match against Clara Burel but the former world number one still managed to claim a 6-1 6-4 victory to move into the third round.

Australian Open champion Aryna Sabalenka, runner-up to Gauff last year, didn’t have to take advantage, polishing off Italian Lucia Bronzetti 6-3, 6-1 in an hour.

Fourth-seeded Alexander Zverev of Germany advanced with a 6-4, 7-6 (7/5), 6-1 victory over France’s Alexandre Muller.

Zverev next faces Argentina’s Tomas Etcheverry, whose efforts to stay hydrated backfired during his 6-3, 4-6, 6-4, 1-6, 6-3 victory over compatriot Francisco Cerundolo.

Sixth-seeded Russian Andrey Rublev and Czech Jiri Lehecka both battled through five sets to line up a third-round meeting.

Rublev, a four-time US Open quarter-finalist, beat France’s Arthur Rinderknech 4-6, 5-7, 6-1, 6-2, 6-2 while Lehecka out-lasted American Mitchell Krueger 6-7 (5/7), 0-6, 6-4, 6-4, 7-5.

Rublev also called medical staff after drinking so much water he felt like he had “a baby” in his stomach.

Elsewhere, seventh-seeded Paris Olympics gold medallist Zheng Qinwen had to go the distance, rallying from a set down for the second straight match to beat Russian Erika Andreeva 6-7 (3/7), 6-1, 6-2.

But eighth-seeded Wimbledon champion Barbora Krejcikova became the biggest upset victim of the tournament so far, bounced 6-4, 7-5 by Romanian qualifier Elena-Gabriela Ruse.

Agencies