Former world number one Simona Halep crashed out of the French Open on Thursday as she failed to deal with the aggressive game of Chinese teenager Zheng Qinwen and suffered a 2-6 6-2 6-1 second-round loss.
Halep, who lifted the trophy at Roland Garros in 2018 before winning Wimbledon the following year, came into the match on Court Simonne Mathieu having won her only prior meeting against the 19-year-old Zheng in straight sets in Melbourne in January.
The 30-year-old Romanian got off to a flying start by dominating play from the baseline, breezing through the opening set and going up a break before Zheng, ranked 74th in the world, took control.
Winners started flowing from the Chinese player's racket as the unforced error count soared for Halep and Zheng did not look back.
Zheng, who hit 28 winners to her opponent's nine, won eight games in a row to go up 3-0 in the deciding set and Halep won just one more game.
"I have been working really hard, and it was really nice, that was my best performance. I am happy today," Zheng said in an interview on court.
Halep also seemed to struggle with her breathing during the third set and had her pulse and blood pressure checked on court.
She said she had suffered a panic attack.
"I didn't know how to handle it, because I don't have it often," a smiling Halep told reporters.
"I don't really know why it happened, because I was leading the match. I was playing well. I couldn't focus. After the match, (it) was pretty tough. But now I'm good. I'm recovered, and I will learn from this episode."
Zheng, playing only her second major after making her Grand Slam debut at the Australian Open, will next meet the winner of the match between local hope Alize Cornet and former champion Jelena Ostapenko of Latvia.
On another day of upsets for the seeded players in the women's draw, American Shelby Rogers beat compatriot and Australian Open finalist Danielle Collins, the ninth seed, 6-4 6-3.
Local wildcard Leolia Jeanjean earlier swept away former world number one and eighth seed Karolina Pliskova in straight sets.