Tennis star Frances Tiafoe issued an apology after going on a profanity-filled rant against a chair umpire. 

Following his loss to Roman Safiullin at the ATP Shanghai Masters event on Tuesday, October 8, Tiafoe, 26, unleashed a tirade against umpire Jimmy Pinoargote. 

“F— you, man! F— you! Seriously, man. F— you!” Tiafoe screamed. “You f—ed me out of the f—ing match! You f—ed the match up! Great f—ing job! F— you! Three f—ing hours I’m f—ing out here battling. Only for my livelihood.”

Tiafoe, who reached the semifinals of the US Open in September, was upset about a questionable time violation given to him by Pinoargote during a crucial moment in the third set tiebreak. 

“I really apologize for the way I acted,” Tiafoe wrote via his Instagram Story on Tuesday. “That is not who I am and not how I want to treat people. I let my frustration in the heat of the moment get the best of me and I’m extremely disappointed with how I handled the situation.”

He continued, “That’s not acceptable behavior and I want to apologize to the umpire, the tournament and the fans.”

While no fine has yet been announced, players are subject to a $60,000 penalty if they “verbally abuse an official.”

In the incident in question, Tiafoe was handed a time violation by Pinoargote at 5-5 in the final set tiebreak. 

“No, no, no, no. I tossed the ball up,” Tiafoe said while walking from the service line to the umpire chair. “No, I tossed the ball up. I was at the line and I tossed the ball up.”

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Tiafoe’s argument fell on deaf ears, with Pinoargote telling him, “I’m not buying it. It’s second serve now.”

The American tennis star remained agitated, yelling “Dude, that’s the rule! The ball goes up, how am I not ready to serve?”

A player is issued a time violation if they do not begin their service motion before the shot clock hits zero. Per the violation, Tiafoe lost his first serve. Tiafoe went on to lose the tiebreak and the match to the unseeded Safiullin. 

Currently ranked No. 17 in the world, Tiafoe advanced to his second US Open semifinal this summer, where he lost to fellow American Taylor Fritz. Last June, Tiafoe rose to No. 10 in the ATP rankings, his highest spot to date.