New York (AFP) - Coco Gauff joined Novak Djokovic and Carlos Alcaraz on the US Open scrap-heap Sunday as the defending champion crashed out to Emma Navarro in a blizzard of mistakes as China’s Zheng Qinwen won a record-setting 2:15 a.m. finish.

As Gauff exited, US chances were then rekindled when Frances Tiafoe and Taylor Fritz reached the men’s last-eight, igniting hopes of a first homegrown male Grand Slam champion since Andy Roddick’s win in New York in 2003.

Third-ranked Gauff slumped to a 6-3, 4-6, 6-3 fourth-round defeat to her fellow American on the back of 19 double faults and 60 unforced errors.

The 20-year-old’s exit means Serena Williams remains the last woman to successfully defend the US Open title, in 2014.

“I lost in the first round the last two years and now to be making the quarter-finals is pretty insane,” said Navarro, who will face Spain’s Paula Badosa for a place in the semi-finals.

Gauff’s loss was another body blow to the season’s final Grand Slam.

Djokovic, the defending men’s champion, was knocked out in the third round to suffer his earliest exit in 18 years.

Fellow crowd-pleaser Alcaraz, the 2022 winner in New York and reigning French Open and Wimbledon champion, was stunned in the second round.

“I gave it my all,” said Gauff. “Obviously there were things execution-wise, where I was like, I wish I could serve better. I think if I did that, it would have been a different story.”

Navarro had defeated Gauff at Wimbledon in July and was dominant again on Sunday from the outset.

The 23-year-old broke for 4-2 in the first set and sealed the opener in the ninth game where one rally stretched to 27 shots.

Gauff recovered from a break down in the second to level the match, but it was a brief respite as she served up three more double faults to slip a crucial break down again in the decider.

- 2:15 a.m. finish -

Zheng reached the quarter-finals for a second time with victory over Donna Vekic in a record late finish for a women’s match.

Seventh-seed Zheng won 7-6 (⁷⁄₂), 4-6, 6-2 against her 24th-ranked Croatian opponent who she also defeated in the Paris Olympics final four weeks ago.

The early Monday morning finish was two minutes later than the old record of 2:13 a.m. from 2021, when Maria Sakkari beat Bianca Andreescu in a last-16 tie.

“I like to play in the night session. Here in New York it’s my first time,” said Zheng in front of a few hundred spectators in the 24,000-capacity Arthur Ashe Stadium.

The powerful 21-year-old is only the second Chinese woman to appear in two quarter-finals in New York after Li Na in 2009 and 2013.

Zheng will next face world number two Aryna Sabalenka who defeated her in the last-eight in 2023 as well as in the final of the Australian Open in January.

Sabalenka eased into a fourth successive quarter-final with a 6-2, 6-4 win over Belgium’s Elise Mertens.

Tiafoe joined former champions Andre Agassi, Roddick and Pete Sampras as the only American men to reach at least three US Open quarter-finals since 2000.

The 20th-ranked Tiafoe notched a 6-4, 7-6 (⁷⁄₃), 2-6, 6-3 victory over Alexei Popyrin, who shocked Djokovic in the previous round.

Tiafoe saved three set points in the second set and will face Bulgarian veteran Grigor Dimitrov for a place in the semi-finals.

The 26-year-old became the second American man to reach the quarter-finals after Fritz defeated Casper Ruud earlier.

Tommy Paul can make it three, but he has to get past world number one Jannik Sinner on Monday.

“I used to hit the ball off a wall dreaming about playing on Arthur Ashe Stadium where the Williams sisters won and where (Roger) Federer won like a million times,” said Tiafoe. “I want to be part of that.”

- Zverev in last eight -

Dimitrov, the ninth seed, put out Russian sixth seed Andrey Rublev, 6-3, 7-6 (⁷⁄₃), 1-6, 3-6, 6-3 to return to the quarter-finals for the first time since 2019 when he defeated Federer on the Swiss legend’s final appearance in New York.

Alexander Zverev, who blew a two-set lead to lose the 2020 final to Dominic Thiem, made his fourth quarter-final by beating Brandon Nakashima of the United States, 3-6, 6-1, 6-2, 6-2.

Up next is a last-eight clash with 12th seed Fritz who knocked out 2022 runner-up and eighth-ranked Ruud 3-6, 6-4, 6-3, 6-2 to reach his third Grand Slam quarter-final this year.

Earlier, New York-born Badosa reached her first US Open quarter-final with a 6-1, 6-2 win over China’s Wang Yafan.