Coco Gauff loses an argument with the chair umpire and a match to Donna Vekic at the Paris Olympics

Coco Gauff was left in tears after getting into an extended argument with the chair umpire over a ruling during the reigning U.S. Open champion's 7-6 (7), 6-2 loss to Donna Vekic of Croatia in a Paris Olympics third-round singles match Tuesday.

Gauff, a 20-year-old American, already was trailing by a lot when the episode happened two games from the end of the match.

Gauff hit a serve and Vekic's return landed near the baseline. A line judge initially called Vekic's shot out; Gauff did not keep the ball in play. Chair umpire Jaume Campistol thought Vekic's shot landed in and awarded her the point, giving her 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.”