Wimbledon champion Barbora Krejcikova was knocked out of the U.S. Open in the second round on Wednesday, defeated by Elena-Gabriela Ruse 6-4, 7-5.

The No. 8-seeded Krejcikova won her second Grand Slam singles title this summer, but then she didn't play any matches after the Paris Olympics. She acknowledged last week not knowing where her level of play was.

Turns out, it wasn't good enough.

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“I mean, winning Wimbledon is amazing. It’s a great, great, great result, I’m very proud about it and how I was able to handle everything there,” said Krejcikova, who hadn't played a tournament on hard courts since February.

“I think I was playing quite well, definitely better than in the first match. I think my game was improving, but it just wasn’t enough.”

Ruse got much more work on the U.S. Open's hard courts while playing her way into the main draw through the qualifying tournament and was better than Krejcikova on the points that mattered most, fighting back from a 5-3 deficit in the second set to win the final four games.

“Barbora, she's such a good player, she's won so many matches in the last two years and it’s just a dream for me,” said Ruse, a 26-year-old from Romania.

No woman has won Wimbledon and the U.S. Open in the same year since Serena Williams in 2012.

Ruse advanced to the third round of a Grand Slam for the first time and will play No. 26 seed Paula Badosa, who eliminated American Taylor Townsend 6-3, 7-5.

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Badosa continued her resurgence in a strong summer by reaching the third round of the U.S. Open for the first time.

“I know it’s just a third round, but I was really looking forward to doing this in New York,” said Badosa, a Spaniard who was born in New York.

Another women's third-round match will see No. 14 seed Madison Keys against No. 33 Elise Mertens. Keys rolled past Maya Joint 6-4, 6-0, while Mertens knocked out Ajla Tomljanovic 6-3, 6-2.

Defending champions Coco Gauff and Novak Djokovic were on the schedule Wednesday night.

The first men's third-round matchup to be determined will have No. 9 seed Grigor Dimitrov, who reached the U.S. Open semifinals in 2019, against Tallon Griekspoor. Dimitrov swept past Rinky Hijikata, while Griekspoor advanced when No. 21 seed Sebastian Baez stopped playing in the second set of their match.