Johnny Depp has denied he slapped his ex-wife Amber Heard after she laughed at one of his tattoos, as he appeared at a hearing at London's High Court.
Mr Depp, 57, is suing the publisher of the Sun newspaper over an article that referred to him as a "wife beater".
Giving evidence, Mr Depp agreed he had "fallen off the wagon" at the time of the alleged incident but said it was "patently untrue" he had hit Ms Heard.
The Sun has defended the accuracy of the 2018 article.
It had referred to "overwhelming evidence" that Mr Depp attacked Ms Heard, 34, during their relationship - which he strenuously denies.
The actor's action is against the publisher of the Sun - News Group Newspapers (NGN) - and executive editor Dan Wootton.
Ms Heard claims that Mr Depp first hit her in early 2013 - one of 14 separate allegations of domestic violence, all denied by Mr Depp, which are being relied on by NGN in their defence.
NGN's lawyer Sasha Wass QC asked Mr Depp about an alleged incident in March 2013 involving Mr Depp's tattoo which reads "Wino Forever".
It had originally said "Winona Forever" in reference to his relationship with actress Winona Ryder, but he had changed it when they split in 1993.
Ms Wass said Ms Heard had made a joke out of the tattoo at a time when he was drinking heavily after about 160 days of sobriety.
Mr Depp replied: "I don't recall any conversation."
Ms Wass said the actor then slapped his ex-wife across the face. She added: "You slapped her more than once, because after you slapped her the first time, she didn't react, she just eyeballed you, she just stared at you, and that made you more angry and you slapped her again."
Mr Depp answered: "That is patently untrue." When he was told he had slapped he three times in total, Mr Depp said: "I'm sorry but that is not true, you are mistaken."
The barrister then put it to Mr Depp that he "broke down" after coming to his senses and realising what he had done, to which he said: "I didn't hit Ms Heard."
The second day of Mr Depp's cross-examination had begun with the actor being asked whether he was taking cocaine in March 2013.
Mr Depp replied that it was "difficult to recollect if I was taking cocaine in March 2013... it's possible".
Ms Heard was also in court in London for the second day running of the case.
On the first day of the libel case the court heard that Mr Depp denied being violent towards his ex-wife and accused Ms Heard of being violent towards him.
NGN previously tried to have the case thrown out, but Mr Justice Nicol ruled last week the case could go ahead.
The case arose out of the publication of an article on the Sun's website headlined: "Gone Potty: How can JK Rowling be 'genuinely happy' casting wife beater Johnny Depp in the new Fantastic Beasts film?"
The Sun's original article related to allegations made by the actress, who was married to the Pirates of the Caribbean star from 2015 to 2017.
Witnesses including Mr Depp's former partners Vanessa Paradis and Winona Ryder are expected to give evidence via video link, and the hearing is expected to last for three weeks.
Mr Depp, 57, has been Oscar and Bafta-nominated and won a Golden Globe in 2008 for Sweeney Todd: The Demon Barber of Fleet Street.