Daniil Medvedev was asked by the umpire not to shout at a line judge during his straight sets win over Gael Monfils at the Monte Carlo Masters.
Russia's Medvedev, 28, was leading 6-2 1-2 when he became angry and disagreed with two calls on the baseline and shouted at the official.
Umpire Mohamed Lahyani twice came on to court to check calls and calm him down.
"Daniil please don't shout at him," Lahyani said. "He [line judge] can make a mistake as well."
Despite being 40-15 up in the incident-packed game, the world number four lost his serve and then went 4-1 down before winning five games in a row to seal victory against the Frenchman.