Denis Shapovalov was livid when he was not allowed to take a bathroom break midway through his Australian Open first-round win over Jannik Sinner.
Canada's 11th seed eventually saw off the up-and-coming Italian in five sets, 3-6, 6-3, 6-2, 4-6, 6-4 in a match which finished around 1am, local time.
The umpire wouldn't allow Shapovalov to head off court after the fourth set - which he had dropped to his opponent.
Djokovic eases past Wawrinka to reach 16th straight Italian Open quarter-final
"What happens if I go?", he asked, "Do I get a fine? I don't care!
"What do you mean I can't go? Are you going to disqualify me? I have to pee!"
'I'm going to p*** my pants!' - Shapovalov blows top over bathroom break
It became evident that he was not going to be permitted to relieve himself off court - and the 21-year-old stepped up his tirade at an umpire who seemed to be amused by the entire saga.
"I'm going to p*** my pants!" he declared.
"I'm going to p*** in a bottle!
"You guys are not allowing players to p***? I don't understand this rule!"
Highlights | Denis Shapovalov - Jannik Sinner
On commentary, Eurosport's Simon Reed offered a sympathetic voice.
"It's a crazy rule," he said. "He's got a point. It's absolutely ridiculous. Why on earth can he not go to the toilet right now? It is unfathomable."
- Top five shots, day one - Monfils’ no-look volley, Kyrgios’ trick shot
- Day one fireworks: Kyrgios hits back at 'very strange cat' Djokovic
- Australian Open 2021 order of play - Nadal, Barty, Kenin day two action
Speaking after the match, Shapovalov cut a calmer figure and didn't blame the umpire, but called for the regulations to change: "I was just blowing off steam, just kind of cooling my head, getting rid of it.
"But also, I do think it's a dumb rule. Especially for me, I've got the smallest bladder ever, so I literally got to take a p*** every set. So it's difficult, especially when you're on that court for so long.
"Before the match I'm trying to hydrate as much as possible, so yeah, I gotta pee, man."
The Australian Open is live on Eurosport. Watch every match live and ad-free on the Eurosport app and eurosport.co.uk. You can download the Eurosport app for iOS and Android now.
Sinner taken to three but eventually grinds past compatriot Fognini
Highlights: Home favourite Sinner knocks out Martinez in Rome