American tennis star Frances Tiafoe could be hit with a monster fine after he launched an X-rated tirade at an umpire.

Tiafoe tasted defeat against Roman Safiullin in the round of 32 at the Shanghai Masters 5-7, 7-5, 7-6 (7-5).

Tiafoe tore into the umpire after his loss at the Shanghai MastersTennisTV

As the two gathered at the net to shake hands, Tiafoe congratulated his rival before he unleashed on the official.

“F*** you, man,” Tiafoe said.

“F*** you. Seriously, man. F*** you. You f***** in the f****** match.”

Unsurprisingly Tiafoe did not shake hands with the official.

It wasn’t long before footage emerged of the moment that sparked Tiafoe’s shocking brain explosion.

With the score locked at 5-5 in the third set tiebreak and on serve, Tiafoe tossed the ball up but appeared to have little intention of hitting the ball just before the serve clock hit zero.

After the ball bounced, the umpire hit Tiafoe with a time violation and put him onto his second serve.

Tiafoe was left furious and made his way to the umpire’s chair.

“No, I tossed the ball up,” Tiafoe said.

“I was at the line and I tossed the ball.”

The umpire responded: “I’m not buying this, it’s the second serve now, OK?”

Tiafoe clapped back: “I tossed the ball, I’m ready to serve. Dude, that’s the rule. The ball goes up, how am I not ready to serve?”

Resigned to his fate, the American trudged back to the service line.

A thrilling 12-point rally ensued that was won by Safiullin thanks to a brilliant cross-court volley, who subsequently won the following point and the match.

Safiullin will face tennis superstar Novak Djokovic in the round of 16 on Wednesday.