New Zealand-born actor Russell Crowe and New Zealand Warriors rugby league team owner Eric Watson had to be separated after brawling in the toilets of a trendy London restaurant, according to British reports.
Ex-EastEnders actor Ross Kemp reportedly leaped in to separate Crowe, 38, and Watson, also in his late thirties, after they came to blows in Zuma restaurant, near Harrods, yesterday, The Sun newspaper said.
Security staff were forced to call police when the fight broke out just after midnight.
Police have spoken to Crowe and Watson and warned them about their behaviour. Police said neither man wanted to lay charges.
It was the latest in a long line of violent episodes that have dogged Crowe, who won an Academy Award for his performance in Gladiator.
The Sun reported Crowe went to Zuma, which attracts celebrities, heads of state and foreign royalty, at 8.30pm on Tuesday (8.30am Wednesday NZT).
Watson, one of New Zealand's wealthiest men, was already at the restaurant.
The pair began arguing in the toilets and then started hitting each other.
The Sun said one of Crowe's two minders heard the commotion and ran to the toilet to find Crowe on the ground and Watson hitting him.
The men were separated but the trouble then spilled out into the main bar area.
Kemp, 37, lunged forward to split up the fighting pair.
The Sun reported one customer as saying, "all hell broke loose for a few moments and Crowe completely lost it."
It was alleged Crowe had been throwing plates around the restaurant before the brawl.
One customer said: "He was out of control. To begin with it was funny. He was throwing plates and it was like something out of the movie My Big Fat Greek Wedding.
"But then the booze wore on and he turned aggressive and nasty. It was sad to see him in that state."
Pony-tailed Crowe suffered scratching round his eye and swelling to his face and forehead.
Watson also sustained marking to his face, The Sun said.
Crowe then appeared to become involved in an argument with a woman, thought to have been with Watson at the bar.
The Metropolitan Police Territorial Support Group raced to the scene in vans and cars after bar staff dialled 999.
Police spoke to both Crowe and Watson in the bar area of Zuma, where a meal with drinks for two in Japanese-themed surroundings costs £100 ($323).
A Scotland Yard spokesman told The Sun: "Police were called at 00.42am to the Zuma restaurant and bar in Raphael St, Knightsbridge, to reports of an altercation involving two men in their thirties.
"When police arrived the situation was under control. No allegations of crime were received."
Crowe, famed for his roles in LA Confidential and A Beautiful Mind, went to Britain last week for the funeral of his fellow actor and drinking buddy Richard Harris.
Watson has a retail and finance empire. He owns racehorses and the New Zealand Warriors rugby league club.
He moved to London a month ago -- about the same time his separation from his wife Nicky was revealed.
Crowe has repeatedly been caught up in fights in recent years:
* In February, he attacked BBC executive Malcolm Gerrie, 51, at the Bafta awards.
* In August, pint-sized singer Moby said Crowe attacked him in a nightclub, and Crowe allegedly attacked another actor while filming in Mexico.
* Two years ago, Crowe was caught on video fighting in a bar near his Australian ranch after chatting up two local girls.
* In 1998, Crowe had to be rescued by the Canadian police after sparking a fight by insulting locals in a bar.