Joaquin Phoenix had to be dragged away by security guards after he jumped off stage and confronted an audience member during a short performance at a Miami Beach nightclub early Thursday.
According to news agency AP, it is unknown whether the confrontation - and his pledge to quit acting and start rapping - was real or a put-on, but actor Casey Affleck recorded the performance on camera.
In October, Phoenix's publicist confirmed he was making the career switch. In January he performed at a Las Vegas nightclub and the next month he made a strange appearance on David Letterman's 'Late Show.'
Actor Ben Stiller lampooned that appearance at the Oscars. Phoenix came out on stage for his performance on Thursday wearing a disheveled dark suit, sneakers and his scraggly long hair and beard.
During his set he responded to someone who appeared to be heckling him in the audience near the stage.
"We have a (double-expletive) in the audience," he said before jumping into the crowd. It was not immediately clear whether the two men exchanged any blows.
"I saw the guy screaming at Joaquin, and Joaquin just came down," said Jorge Lledo, 30, of Miami Beach.
Security guards swarmed the scene and dragged Phoenix away.
