Newly crowned French Open champion Coco Gauff was stunned in her return to action Thursday, losing to Chinese qualifier Wang Xinyu 6-3, 6-3 at the Berlin Open.
The second-ranked Gauff, who won at Roland Garros less than two weeks ago for her second Grand Slam title, amassed 25 unforced errors and seven double faults in the defeat.
Gauff had a bye to the second round at the grass-court tournament, a warmup for Wimbledon.
"It was a tough one today but happy to be back on court," Gauff wrote on her social media accounts. "Tried my best to adjust with the quick turnaround but it wasn't enough. As always, I'm learning as I go so I hope to do better next time."
The 21-year-old Gauff added that she is "excited to get some more practices in to be ready for Wimbledon," which starts June 30. She has not made it past the fourth round at the All England Club.
Wang, ranked No. 49, said she would have been pleased just with the first set, considering the level of her opponent.
"After I won the first set, I just told myself, 'OK, let's take a minute and enjoy this, I'm playing the French Open champion, and I won the first set,'" Wang said in her on-court interview. "No matter how the second and third go, I was like, 'OK, let's just enjoy it for a second.'
"I'm really happy with how I played today. I was serving good and putting a lot of pressure on the return, especially second-serve return."
Gauff looked uncomfortable on the slick grass and was broken in the seventh game. Wang clinched the set after Gauff double-faulted on deuce and then sank a drop shot into the net on set point.
Gauff broke to go 3-1 up in the second set, but Wang ran off five games in a row for the victory.
Aryna Sabalenka, also playing for the first time since losing to Gauff in the French Open final, completed a 6-2, 7-6 (6) win over Rebeka Masarova to reach the quarterfinals, concluding a match that had been suspended Wednesday because of slippery conditions.
Sabalenka had been up a set Wednesday when play was stopped after tournament officials said the court was getting too slippery with humidity rising after sunset.
When the match resumed Thursday, the 27-year-old was broken at the start of the second set and found herself 3-1 and 4-2 down. She kept her cool, however, and broke back with a fine volley to force a tiebreak.
Sabalenka squandered two match points before sealing victory at her next opportunity when Masarova sank a midcourt forehand into the net. She will next face Elena Rybakina of Kazakhstan.
Marketa Vondrousova, the 2023 Wimbledon champion, needed three sets and 2 hours, 20 minutes, to break the resistance of Diana Shnaider.
Vondrousova, who was 6-5 and 30-0 up in the second set, advanced with a 6-3, 6-7 (3), 6-3 win and will face lucky loser Ons Jabeur, a two-time Wimbledon finalist, in the quarterfinals.
The Associated Press and Reuters contributed to this report.