Champion Gauff makes early exit from US Open, Zverev into last eight

Coco Gauff's US Open title defence ended in a 6-3 4-6 6-3 loss to fellow American Emma Navarro in the fourth round on Sunday, the reigning women's champion becoming the latest big name to make an early exit at Flushing Meadows this year.

Gauff had been looking to avenge her fourth-round loss at this year's Wimbledon but Navarro stunned the crowd at Arthur Ashe Stadium with an aggressive all-round display to reach the quarterfinals for the first time.

Third seed Gauff fought her way back into the match after going a set down but ultimately 19 doubles faults and 60 unforced errors meant her first defence of a Grand Slam title was destined to end in disappointment.

"Mentally and emotionally, I gave it my all," said 20-year-old Gauff, who will now drop out of the top five in the world rankings.

"Of course, there were things execution-wise, obviously I wish I could serve better. I think if I would have did that, it would have been a different story for me. But Emma played really well. She did everything well, I thought."

In men's action, Alexander Zverev, Grigor Dimitrov, Taylor Fritz and Frances Tiafoe all marched into the quarterfinals in the bottom half of the draw which was left wide open after the third-round exit of four-times champion Novak Djokovic.

Zverev, still searching for his first Grand Slam title at the age of 27, reached the quarterfinals at a major for the 13th time after coming from a set down to beat American Brandon Nakashima 3-6 6-1 6-2 6-2.

"I'm still very motivated," said the German, who lost to Dominic Thiem on a deciding set tiebreak in the 2020 final.

"I still want to achieve some of my dreams. I still want to achieve some of my goals that I have. I'm happy with the level of tennis I'm playing. We'll see how this week goes."

The fourth seed will next face another American in Fritz, who overcame a sluggish start to beat Norwegian Casper Ruud, the losing finalist in 2022, 3-6 6-4 6-3 6-2.

Fritz was later joined in the quarterfinals by Tiafoe, another player hoping to take advantage of the early exits of Djokovic and Carlos Alcaraz to end America's 21-year wait for a homegrown men's champion.

Alexei Popyrin ousted Djokovic in a huge shock on Friday but was unable to progress any further as Tiafoe, roared on by a noisy evening crowd on Arthur Ashe, ran out a 6-4 7-6(3) 2-6 6-3 winner.

It was not all plain-sailing for the 20th seeded American, who had to dig deep to battle back from 5-2 down in the second set against the big-serving Australian.

Tiafoe, though, broke for 4-2 in the fourth on a Popyrin double fault and held firm to set up a quarterfinal against Dimitrov, who was earlier cheered on by Serena Williams as he downed sixth seed Andrey Rublev 6-3 7-6(3) 1-6 3-6 6-3.

• Defending champion Djokovic knocked out of US Open third round

• Sports