A fan was ejected from a U.S. Open tennis match early Tuesday morning after German player Alexander Zverev complained the man used language from Adolf Hitler’s Nazi regime. (More Tennis News)

Zverev, the No. 12 seed, was in the fourth set of his match against No. 6 Jannik Sinner when he suddenly went to chair umpire James Keothavong and pointed toward the fan, who was sitting in a section behind the umpire.

Keothavong at first asked fans to be respectful to both players. However, during a changeover shortly after, the fan was identified by spectators seated near him, and he was removed by security.

“A disparaging remark was directed toward Alexander Zverev,” U.S. Tennis Association spokesman Chris Widmaier said, “The fan was identified and escorted from the stadium.”

Zverev went on to beat Sinner in five sets and will play defending U.S. Open champion Carlos Alcaraz in the quarterfinals.