Bernard Tomic has delivered a foul-mouthed spray to a heckler during his first-round match at the US Open in New York.
French umpire Cedric Mourier advised Tomic to go through the official channels rather than take matters into his own hands after the Australian told the fan to "suck my balls" during his 6-4, 6-3, 4-6, 7-6 (0) defeat to Damir Dzumhur on Tuesday.
"I will put my balls in your mouth" and "I will give you some money to make you feel good," Tomic said for all to hear on the Old Grandstand court at Flushing Meadows.
"He was saying some s---," Tomic added to Mourier when the umpire questioned why he'd lashed out.
"It's better you go through me than try to solve it by yourself," Mourier said.
The incident occurred early in the third set with Dzumhur serving with a two-sets-to-love lead.
Tomic regained his cool to win the third set to stay in the match, but couldn't force a decider after being blown away in a fourth-set tiebreak.
"I think he was just baiting me a bit," Tomic later told a press conference. "I don't want to get into it. I apologised for what I said to him. I think after he left [after] the first set, I think the crowd got happy he left because he was a bit annoying.
"He [the chair umpire] just asked me who was that, what was this. I just said some guy. I don't know who it was. The whole time I didn't know who it was. I'm focusing on the court. That's my priority.
"There was some stuff in the background as I was playing balls and returning. It's tough. I watched a little bit today of [Janko] Tipsarevic also and [Sam] Querrey. There were some similar situations with the crowd yelling and people talking in between points. Big points, I should say.
"It was maybe not good that the crowd got too excited or sometimes speaking in the points, it's not fair. I think we're here to all play and everything has to be equal."
Tomic's Davis Cup teammate Nick Kyrgios was fined and placed on a six-month suspended ban for his infamous "Kokkinakis banged your girlfriend, by the way" sledge, which was directed at Swiss star Stan Wawrinka at last year's Toronto Masters.
Information from AAP contributed to this report.