Actor Will Smith stormed the Oscars stage and hit comedian Chris Rock across the face for joking about his wife.
Rock had made a joke comparing Jada Pinkett Smith's short hair to Demi Moore's appearance in the film "G.I. Jane" and suggesting she appear in a sequel.
Smith strode up to Rock and slapped him, before returning to his seat alongside Jada and shouting profanities.
"Keep my wife's name out of your f*cking mouth," yelled Smith, forcing the producers to bleep out several seconds of audio from the televised broadcast in the United States.
Jada Pinkett Smith, who is also an actress, suffers from alopecia, which can cause hair loss and balding.
Minutes later, when accepting the Oscar for best actor for his role in "King Richard", Smith apologised to the Academy of Motion Picture Arts and Sciences and his fellow nominees but not to Rock.