LOS ANGELES, MARCH 27

Best actor winner Will Smith 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 Jada Pinkett Smith's hairstyle in an epic moment overshadowing the Oscars ceremony on Sunday.

Minutes later, when accepting his first Oscar for best actor for his role in "King Richard," Smith apologized to the Academy of Motion Picture Arts and Sciences and his fellow nominees in a tear-filled acceptance speech, but not to Rock.

"I want to be a vessel for love," Smith said, with tears streaming down his face during his acceptance speech.

It was unclear whether Rock, a comedian and actor, was aware that Smith's wife, Jada Pinkett Smith, suffers from a disease that causes hair loss.

The episode with Rock, upstaging the rest of the 3-1/2 hour show, was sure to become one of the most memorable moments in 94 years of Academy Awards.

The incident at first appeared to be a scripted joke but turned serious when Smith shouted: "Keep my wife's name out of your fucking mouth."

The audio from the show, broadcast on a time-delay of a few seconds in the United States, appeared to have been cut from the live transmission for many viewers because of the language. But it was audible in some broadcasts, for example in Japan and Australia.

Rock was roasting some of the nominees and, after mentioning Smith, said of his wife, "Jada, I love you. 'G.I. Jane II,' can't wait to see it."

He was referencing the 1997 film "G.I. Jane" in which actress Demi Moore shaved her head.

Smith then walked on stage toward Rock, who had his hands behind his back when Smith threw an open hand at his face that produced an audible smack, and in a form befitting an action movie star. Rock somehow stayed on his feet.

"Oh, wow! Wow! Will Smith just smacked the shit out of me," Rock said as the audience laughed, thinking it was a skit. "Wow, dude. It was a 'G.I. Jane' joke."

Smith then made what may become one of the most repeated phrases of Oscar history when he said, "Keep my wife's name out of your fucking mouth."

Rock responded, "I'm going to. That's the greatest night in the history of television."

Smith then repeated his phrase, louder and more deliberately.

Jada Pinkett Smith told Billboard in December she has been battling the autoimmune disorder alopecia, which can cause hair loss and balding.

The audience initially thought Smith's indignation was feigned, part of the act.

It was only after he returned to his seat and shouted that the audience went silent and audibly gasped. Many people in the mezzanine stood up and craned their heads to try to catch a glimpse.

Rock has hosted the Oscars twice, in 2005, when he received mixed reviews, and again in 2016 when, during the #OscarsSoWhite protests, he confronted the Academy over the lack of Black representation.

Smith, 53, has been one of Hollywood's most charming and bankable stars, and was known for his clean rap lyrics when he shot to fame in the 1990s in the television sitcom "The Fresh Prince of Bel-Air."

He took on mostly comedy and action roles early in his movie career before expanding into drama, and twice had been nominated for best actor before, for 2001's "Ali" and the 2006 movie "The Pursuit of Happyness."

Smith won this time for playing Richard Williams, the father of tennis stars Venus and Serena Williams.

"Richard Williams was a fierce defender of his family," Smith said through tears in an obvious reference to what had just taken place.

Smith did not mention Rock but said: "Art imitates life - I look like the crazy father, just like they said about Richard Williams. But love will make you do crazy things."

Smith, who laced his speech with religious references, also told the audience what fellow nominee Denzel Washington said to him moments earlier: "At your highest moment, be careful, that's when the devil comes for you."

And his final remark before leaving the stage was, "I hope the Academy invites me back."