Defending champion Coco Gauff became the latest big-name casualty to exit the U.S. Open when Emma Navarro won their fourth round match 6-3 4-6 6-3 to down her stunned American compatriot for the second time in a Grand Slam this year.

Gauff had been looking to avenge her defeat by Navarro at Wimbledon, where she lost in the fourth round, but the 13th seed stunned the crowd at Arthur Ashe Stadium on Sunday with an aggressive and dominant all-round display that had Gauff searching for answers.

Gauff was her own worst enemy, however, especially on serve where the 20-year-old third seed struggled and had 19 double faults — as many as she had in her first three matches combined — while she also made 60 unforced errors.