Coco Gauff of United States

PARIS — Coco Gauff got 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.

Gauff 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.