Best actor nominee Will Smith has smacked presenter Chris Rock in the face with an open hand and shouted a vulgarity at the comedian for making a joke about his wife's appearance at the Oscars ceremony.<br /><br />Rock made a joke about the hairstyle of Smith's wife Jada Pinkett Smith that referenced the movie G.I. Jane, in which actress Demi Moore shaved her head.<br /><br />Smith, who is nominated for best actor for King Richard, stormed onto the stage and slapped Rock in what at first appeared to be a scripted joke.<br /><br />But the mood turned sombre moments later when Smith, back in his seat, shouted back, "Keep my wife's name out of your f***ing mouth".<br /><br />A clearly shaken Rock went on to present the award for best documentary feature to Summer of Soul (Or, When The Revolution Could Not Be Televised).