Viewers at home, and even fellow Hollywood stars in the room at the Dolby Theatre, were in shock - particularly Lupita Nyong'o, who was sitting behind Will and whose reactions could be seen live on the broadcast.
Much like Lupita, viewers had no idea whether or not the altercation was real or fake at the time.
However, the fact that Will was swearing and the broadcast was therefore muted in the United States, makes it appear that the incident was not in fact a "scripted bit" put on by producers but a very real incident.
Following the altercation in the ad break, Will was seen being comforted by Tyler Perry, Bradley Cooper and Denzel Washington before returning to his seat.
The 53-year-old actor also addressed the incident shortly after, in his acceptance speech for the Best Actor award for his role in King Richard.
"Denzel [Washington] said to me, at your highest moment, be careful — that’s when devil comes for you," he said, before adding through tears, "I want to apologise to the Academy, I want to apologise to my fellow nominees."
The following day, Will released an official statement via his Instagram page in the wake of the backlash.
"Violence in all of its forms is poisonous and destructive," the actor wrote. "My behaviour at last night’s Academy Awards was unacceptable and inexcusable. Jokes at my expense are a part of the job, but a joke about Jada’s medical condition was too much for me to bear and I reacted emotionally.
"I would like to publicly apologise to you, Chris. I was out of line and I was wrong. I am embarrassed and my actions were not indicative of the man I want to be. There is no place for violence in a world of love and kindness.
"I would also like to apologise to the Academy, the producers of the show, all the attendees and everyone watching around the world. I would like to apologise to the Williams Family and my King Richard Family. I deeply regret that my behaviour has stained what has been an otherwise gorgeous journey for all of us.
"I am a work in progress," he finished, signing off "sincerely, Will."
It's not the first time Will, Jada and Chris have been involved in an Oscars-blow-up.
In 2016 when he hosted the ceremony, Chris joked about Jada announcing she was boycotting the awards due to racism in Hollywood as the #OscarsSoWhite hashtag took hold of social media.
"This is the wildest Oscars to host - no black nominees. People are like 'Chris you should quit!' How come it's only unemployed people that tell you to quit something? I thought about it," Chris said in his opening monologue.
"What happened this year? People went mad! Jada went mad! Jada said she's not coming. Isn't she on a TV show?
"Jada boycotting the Oscars is like me boycotting Rihanna’s panties - I wasn’t invited... that's not an invitation I would not turn down," the star said at the time, much to the shock of the audience.
The Los Angeles Police Department said it was aware of a slapping incident at the Oscars but said the person involved had declined to file a police report. Outside of this, Chris is yet to address the incident publicly.