Coco Gauff broke down in tears after a controversial call during her loss in the Olympics on Tuesday.

The world No. 2 and reigning U.S. Open champion ultimately fell to Donna Vekic of Croatia, 7-6(7), 6-2 in the third round of the Paris Olympics.

Gauff faced a break point serving at 2-3, 30-40 in the second set. Vekic hit a return deep to Gauff’s forehand, which the American mishit into the net. Vekic’s shot was called out by the line umpire, who then immediately corrected the original call, and the point was awarded to the Croatian. The umpire could have opted to have the players replay the point, but instead gave it to Vekic.

“I was going back to hit the ball and he called it out before I hit it,” Gauff told the umpire. “That’s why I went up on the ball.”

She added: “I never argue these calls but he called it out before I hit the ball….It always happens to me on this court,” Gauff said as she broke into tears.

Clare Wood, the tennis competition manager for the Olympics, was eventually called to the court.

“You have to understand, he called it out before I hit it,” Gauff explained. “What’s the rule? It’s not even a millisecond, he called it when I hit the ball. I understand if it was the same time but it was before. It’s not even a perception.”

Former tennis pro Naomi Cavaday was calling the match and said:

“If Gauff had hit the ball into the court it would be a replay but because she missed the shot, the point has been awarded to her opponent because the call was wrong. Gauff’s argument is that it impacted her shot and the call made her miss. When it happens on the baseline there is such little time between the bounce and your swing that the most likely situation is that the call has not impacted your swing because it’s such a reaction, it’s so quick, there’s no time for it.”

Gauff lost the game and failed to win another game in the match.

Last month during her French Open semifinal with world No. 1 Iga Swiatek, Gauff also broke into tears after getting into a heated dispute with the chair umpire.

With Swiatek serving at 0-15, her serve was called out, but the umpire overruled the call. Gauff missed the return but told the umpire she hit the ball after the line call was made.

With Swiatek serving at 0-15, her serve was called out, but the umpire overruled the call. Gauff missed the return but told the umpire she hit the ball after the line call was made.

Gauff approached the chair and said, “Are you serious? They are booing you because you are wrong.”

Gauff was one of three American women into the third round.

Danielle Collins advanced to the fourth round Tuesday with a three-set win over Colombia’s Camila Osorio, while Emma Navarro faced China’s Qinwen Zheng.