Coco Gauff said racist abuse online had left her feeling drained, as the American player fell to Elise Mertens at the China Open.
The world No 4, an African American, produced an unusually flat performance in Beijing on Wednesday, committing eight double faults in a 3-6, 3-6 defeat to the Belgian.
Gauff, 22, played just a day after she spoke out about the flood of "insane" abuse she received online following her win over young Chinese player Sun Xinran in the previous round.
"It's definitely draining. I'm not going to lie," Gauff said of the impact of the online comments. "But I just turned my phone off and kept going. There's nothing you can do about it."
Asked about the match, she said: "I think I didn't play well. I think I didn't move well. There are a lot of things I didn't do well. I think Elise played well on the important points."
In her earlier match in Beijing against Sun, Gauff asked for a video review because LED lights on the advertising boards at the stadium were flickering. The move drew boos from some spectators. The umpire agreed to replay the point, and Gauff went on to win 7-5, 6-1.
Early on Tuesday, Gauff wrote on X: "Hello everyone, you can dislike me or disagree with what happened without being racist." She was responding to a post containing a racial slur. "The amount of racist comments and messages I've received in the past few hours is insane," she wrote.
Gauff also clarified that she had challenged the point before Sun returned the ball, when she noticed the lights flickering for a second time.
Asked about the incident, a spokesperson for the WTA, the global governing body of women's tennis, said it was "horrified by the racist abuse directed at Coco Gauff" and was "reaching out to her to offer our full support". The body added in a statement to AFP that there is no place for racism, discrimination or abuse in tennis, and that it was "looking into how to address" the abusive content.
Gauff, who won Beijing in 2024 and reached the semi-finals last year, is a popular figure with fans at the tournament. A group of supporters in the near-empty stadium tried to urge her to a comeback on Wednesday, but Mertens was unfazed and secured a quarter-final spot against Iga Swiatek.
The world No 19 called Gauff "an amazing player", adding: "I knew this was going to be a very tough match." She dedicated the win to her coach, who is also her boyfriend.
Earlier, Swiatek beat young American Iva Jovic 6-1, 6-3 in one hour 35 minutes. "I controlled the match from the start," said the Polish world No 9. "I feel like I'm improving every day."
China's Zheng Qinwen was scheduled to face Alina Charaeva, ranked 118th, later on Wednesday. Ukraine's Elina Svitolina, the sixth seed, was set to take on Ann Li of the United States.
