The comedian took shots at various members in the crowd after taking to the stage for the 94th Academy Awards.
However, things took a turn when he made joke about the King Richard star's wife Jada Pinkett Smith, suggesting she looked like 'GI Jane'.
Smith then walks up to the stage and shockingly lands a slap on Rock before heading back to his seat.
"Will Smith just smacked the s**t out of me," says the 57-year-old comedian, seemingly rattled by the confrontation.
Although Smith initially appeared amused, he then repeats angrily to Rock, "Keep my wife's name out your f**king mouth."
Chris awkwardly attempts to segue into the next segment, but not before saying, "That was the greatest night in the history of television."
Viewers at home weren't sure whether the incident was staged or not, but a slo-mo video shared on Twitter taken from a different angle at least confirms that the slap was real.
"It was very real," wrote one, while another said, "Slowed down, the smack absolutely made contact."
There are also numerous of opinions on who is at fault here, with one pointing the finger at the producers, stating: "So the Oscars aren't going to do anything about Will Smith assaulting Chris Rock on stage."
Another said: "Will Smith making everything about .... Will Smith. I am all for defending your wife, but it's Chris Rock. He could have spoken to him afterward. Jada commands respect which is great. But it was a joke with no malicious intent.
"I can't believe Will Smith smacked Chris Rock like that after everything Jada put him through."
No doubt there will be plenty more of this kind of chat in the coming days.
Words: Daisy Phillipson