Bad Behavior! American Tennis Star Frances Tiafoe Screams 'F*** You' at Umpire in Furious on-Court Meltdown

Frances Tiafoe has landed himself in hot water after a foul-mouthed rant at the umpire following his loss to Roman Safiullin.

The American world No 17 reacted furiously after being called for a time violation at 5-5 in a crucial third-set tiebreak at the Shanghai Masters.

Tiafoe went on to lose the next two points, allowing Safiullin to secure a 5-7 7-5 7-6 (5) victory.

The world No 61 shook hands with Tiafoe at the net, before the American turned his attention to umpire Jimmy Pinoargote - much to the amusement of the crowd.

The American then suggested he would never let Pinoargote officiate another one of his matches, insisting: 'You’re going to be on the blacklist for my matches, never again.

Players have 25 seconds to serve after the climax of the previous point. With time running out, Tiafoe walked to the baseline and tossed the ball into the air without hitting it.

The umpire called a time violation - Tiafoe's third - meaning the American lost his first serve.

'No, no, no. I tossed the ball up,' the American fumed as he approached the umpire. 'I was at the line and I tossed the ball... I was ready to serve!'

The umpire disagreed - 'I’m not buying it, it’s a second serve,' - prompting Tiafoe to shout: 'Dude that's the rule! If the ball goes up, how am I not ready to serve?'

Tiafoe - a US Open semifinalist in 2022 and 2024 - could face a hefty punishment over the outburst, with ATP rules stating that players can be fined up to $60,000 for verbal abuse.

'Players shall not at any time directly or indirectly verbally abuse an official, opponent, sponsor, spectator or any other person within the precincts of the tournament site,' the ATP states.

'Verbal abuse is defined as any statement about an official, opponent, sponsor, spectator or any other person that implies dishonesty or is derogatory, insulting or otherwise abusive.'

If the incident is investigated, Tiafoe could also see the $59,100 he earned - by reaching the third round in Shanghai - withheld.

ATP rules also state: 'A player shall not use an audible obscenity while on-site. Audible obscenity is defined as the use of words commonly known and understood to be profane and uttered clearly and loudly enough to be heard.

'Violation of this section shall subject a player to a fine up to $5,000 (£3,815) for each violation. In circumstances that are flagrant and particularly injurious to the success of a tournament, or are singularly egregious, a single violation of this section shall also constitute (a) Major Offense of Aggravated Behavior.'