Coco Gauff was left in tears after getting into an extended argument with the chair umpire during her loss to Donna Vekic at the Paris Olympics on Tuesday.

Gauff, the reigning US Open singles champion, was trailing in the second set of her 7-6, 6-2 loss when she tangled with the umpire.

Gauff hit a serve and Vekic’s return landed near the baseline. A line judge initially called Vekic’s shot out, and Gauff did not keep the ball in play. Chair umpire Jaume Campistol thought Vekic’s shot landed in and awarded her the point, giving the Croatian a service break and a 4-2 lead.

Gauff walked over to talk to the official and play was delayed for several minutes. “I never argue these calls. But he called it out before I hit the ball,” Gauff said to Campistol. “It’s not even a perception; it’s the rules. I always have to advocate for myself.”

The American was seeded second in the women’s singles in Paris and easily won her first two matches, dropping a total of just five games. But the 20-year-old’s first Olympic singles tournament – she is still in women’s doubles and mixed doubles – ended with a performance that was far from her best on the hottest day of the Paris Games so far, with the heat rising above 32C (90F) during her match.

Even before the trouble over the umpiring decision, Gauff could not sustain a good start against Vekic, who was a semi-finalist at Wimbledon this month. Gauff led 4-1 and was a point from moving ahead 5-1 and serving for the opening set. But she couldn’t close the deal, then wasted a couple of set points at 6-4 in the ensuing tiebreaker. Vekic surged to the end of that set, then maintained her level in the second. One measure of Vekic’s superiority on this afternoon: She finished with 33 winners to just nine for Gauff.

But the most memorable portion of the match was the second-set dispute. It’s not the first time Gauff has been upset by a call she thought was incorrect, and not the first time at Roland Garros, which hosts the French Open as well as this summer’s Olympic tennis tournament.

There was a similar incident during Gauff’s loss to eventual champion Iga Świątek in the French Open semi-finals last month. After that match, Gauff called it “almost ridiculous” that tennis does not employ video replay technology at all events.

She alluded to the Świątek match while talking to Campistol and a supervisor who joined the conversation on the court on Tuesday. “It always happens here at the French Open to me. Every time,” Gauff said. “This is like the fourth, five time it’s happened this year.”

When Gauff gave up and headed back on court to resume play, fans booed loudly – with their anger seemingly directed at the officials. The first point of the next game went Gauff’s way, and spectators cheered wildly for her. But about 10 minutes later, the match was over.

Gauff said after the match that the disputed call did not lead to her defeat.

“I’m not going to sit here and say one point affected the result today, I was already on the losing side of things,” she said.