Coco Gauff's US Open title defence is over after she was beaten by Emma Navarro in the fourth round in New York.

Third seed Gauff produced a disjointed performance to lose 6-3 4-6 6-3 to fellow American and 13th seed Navarro.

Gauff hit 19 double faults - including 11 in the third set alone - and produced three in the final game of the match to hand Navarro victory.

"I lost in the first round the last two years and now to be making the quarter-finals is pretty insane," said Navarro.

"This is the city I was born in and it feels so special to be playing here."

Gauff was comprehensively beaten by Navarro just two months ago in the last 16 at Wimbledon.

She said she would need to maintain her focus after "collapsing" mentally in their previous meeting - but frailties on serve, including three back-to-back double faults in the third set, and 60 unforced errors helped Navarro reach the quarter-finals at Flushing Meadows for the first time.

Navarro will go on to play 26th seed Paula Badosa in the last eight after the Spaniard thrashed China’s Wang Yafan 6-1 6-2 earlier on Sunday.

"Coco is an amazing player," Navarro added.

"I have a ton of respect for her and I know she's going to come back here and win this thing again."

Navarro’s victory ends Gauff’s bid to become the first woman to defend the US Open title since Serena Williams in 2014.

It also makes the 23-year-old the youngest American woman to reach the quarter-finals at both Wimbledon and the US Open in the same year since Williams in 2004.

It was Navarro who made the brighter start, earning a break point in the opening game of the match after two double faults by Gauff in a sign of things to come.

Gauff recovered to hold, but some loose shots at 3-2 gave Navarro another break opportunity, and Gauff conceded with another double fault.

As Navarro secured the set, confidently holding to love after coming out on top of a 27-shot rally, a frustrated Gauff shrugged her shoulders and exchanged words with her coaching team.

Double faults continued to plague Gauff’s performance in the second set. Another at 3-3 offered Navarro a chance to break, which she took with a superb, dipping forehand winner down the line.

But this would signal a change in momentum as, sensing she was closing in on victory, Navarro suddenly struggled for rhythm, and Gauff immediately broke back.

Backed by the packed crowd, Gauff confidently held serve before breaking again to force a decider, cupping her ear in celebration and asking the crowd for more noise.

With the match evenly poised, it was the 20-year-old's troubles on serve which would again prove the difference, with three double faults in a single game handing Navarro the break for a 2-1 lead.

Gauff’s remaining service games were punctuated by more errors, with three more double faults gifting a match point to Navarro, before a long forehand confirmed Navarro's win.

"I fought really hard today. I just didn't take care of my serve, so that was the biggest difference," Gauff said.

"Mentally and emotionally I gave it my all. Of course, there were things execution-wise, where I wish I could serve better.

"I think if I would did that, it would have been a different story for me in the match."

Navarro will rise into the world's top 10 as a result of the win over Gauff.

A notable college player, Navarro reached her first WTA Tour semi-final in 2023, but went one step further this year, lifting her maiden title in Hobart in January.

She has claimed some eye-catching wins, including over world number two Aryna Sabalenka at Indian Wells, before reaching the fourth round of the French Open.

She has now reached back-to-back Grand Slam quarter-finals, having lost to Jasmine Paolini at the same stage at Wimbledon in July.

"When I first left college, my coach and I kind of made a two-year contract that I would fully commit myself to playing professional tennis for two years and then reassess after that," Navarro told the WTA website., external

"I think I hit the two-year mark this June, and we didn't even acknowledge it or talk about it.

"I definitely have surpassed my expectations for sure."