American Jessica Pegula took a stunning loss at Wimbledon on Thursday, falling to Wang Xinyu 6-4, 6-7(7), 6-1 in the second round. Pegula, seeded No. 5, is the highest seed to lose at the tournament thus far.

Xinyu, 22, came into Wimbledon ranked No. 42 and earned her first victory over a player ranked in the top 10. She is also the first Chinese player to defeat a player ranked in the top five since Zheng Jie beat Ana Ivanovic in 2008.

"Couple of days ago, I was asking my coach, 'When will this happen?'" Wang said after the match. "Jessica was really tough to play on grass. Her ball was super low and I'm just really happy I won in the end."

Pegula, 30, was expected to build on finishing in the quarterfinals last year at Wimbledon with hopes of getting to her first semifinal at a Grand Slam event. Her chances appeared even more encouraging after she won on the grass court at the Ladies Open in Berlin, her first title win in a grass-court tournament.

Xinyu will next face Harriet Dart in the third round. Dart defeated fellow British player and No. 32 seed Katie Boulter 4-6, 6-1, 7-6(8) earlier on Thursday.

It wasn't all bad news for American players at Wimbledon on Thursday.

No. 12 seed Madison Keys earned a straight-set victory over Wang Yafan 6-2, 6-2. She advances to play Marta Kostyuk in the third round.

And on the men's side, No. 14 Ben Shelton won a grueling five-set match over Lloyd Harris 4-6, 7-6(5), 6-7(5), 6-3, 7-6(10-7) that lasted more than three hours. Shelton will next face Denis Shapovalov on Friday.