Sylvester Stallone once knocked out former Chael Sonnen at a UFC event in front of Robert De N

Chael Sonnen may be making headlines for his Twitter spat with Conor McGregor, but the former UFC title challenger may want to take a back step.

The last time the ‘Bad Guy’ took on a name as big as McGregor, Sylvester Stallone ‘punched’ him in the face as Hollywood legend Robert De Niro watched on.

Sonnen and McGregor have been going back and forth on social media ever since a video emerged of ‘The Notorious’ stalking his TV whilst Max Holloway was preparing to fight.

The 44-year-old warned the Irishman he ‘is on the verge of being a rich, little weirdo’, an insult McGregor understandably took umbrage with.

Sonnen has developed a cult following amongst MMA fans for his back chat and witty remarks, yet he broke onto the big stage in 2013 when he starred in the Hollywood blockbuster, Grudge Match.

In his brief cameo alongside both Stallone and De Niro, the former world title contender approaches the ageing boxers at a UFC event after they called MMA fighters ‘girls.’

After confronting De Niro’s character, Sonnen then slaps Stallone, before taking a big right hand and being sent through a nearby table.

Unlike the stunt itself, the film lacked any real punch and was considered a box office flop after making just $45million (£33.5m).

Sonnen reverted back to the cage after his brief stint in the film business, moving to Bellator when his UFC contract expired to fight in the heavyweight division.

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