Actor Will Smith shocked the audience at the Dolby Theatre, and people around the world watching the Oscars ceremony live, when he landed a slap on the face of Chris Rock.
Smith left his front-row seat and stormed onto the stage after the comedian made a joke about his wife, Jada Pinkett Smith's, close-cropped hair. Pinkett Smith has been public about her recent battle with alopecia.
It's not the first time viewers have been left stunned by events at the annual Academy Awards presentation. We recall five previous moments of high drama or farce.
You had one job …
You don't have to go too far back to find one of the most memorable slip-ups in Oscars history.
In 2017, the musical La La Land was wrongly declared winner of the best picture Oscar instead of the intimate indie drama Moonlight. Warren Beatty and Faye Dunaway made the announcement, and the mix-up continued for two minutes and 23 seconds.
La La Land producers Jordan Horowitz, Marc Platt, and Fred Berger had given their acceptance speeches before the mix-up came to light.
It was later revealed that two PricewaterhouseCoopers accountants had handed the presenters the wrong envelope — it was a duplicate for the best actress award, which had earlier been won by Emma Stone for La La Land.
Jennifer Lawrence takes a tumble
In 2013, the actress became a viral sensation while walking to the stage to collect an Oscar for best actress for her role in Silver Linings Playbook.
Lawrence added some extra drama to the night when she tripped on her dress and fell on the steps leading to the stage. The audience still gave her a standing ovation.
Another smack — this one on the lips
In 2003, the internet blew up after a move by actor Adrien Brody. The star casually made his way to the stage to accept the best actor Oscar for his role in The Pianist, then gave surprised presenter Halle Berry a kiss on the lips.
Showing his shortcomings
In 1974, David Niven was about to introduce Elizabeth Taylor, his co-host for the 46th Academy Awards, when a streaker stormed the stage. The man was artist and gay rights activist Robert Opel who had apparently got backstage by posing as a journalist.
Niven quipped: "Isn't it fascinating to think that probably the only laugh that man will ever get in his life is by stripping off and showing his shortcomings?"
Brando takes a stand ... by not taking to the stage
In 1973, Marlon Brando won the best actor Oscar for his role in The Godfather . But as a protest against Hollywood's portrayal of Native Americans, he boycotted the ceremony. Native American activist Sacheen Littlefeather took to the stage on his behalf, but refused to accept the statuette from presenter Roger Moore.
This article was first published in South China Morning Post.