Kevin Hart: I'm a Pro, Damnit! Roasts the Hell Out of MC

Kevin Hart ain't got time for amateurs ... something a Hollywood nightclub MC learned the hard way when he foolishly tried to go insult-for-insult with Kevin in front of the whole club.

The impromptu roast broke out at Project Club LA over the weekend. The MC, Branden King, got Kevin onstage to pump up the crowd for the Halloween party. Good move on Branden's part.

The bad move came when he decided to retaliate after Kevin ribbed him about not dressing up for Halloween. Branden dared to bust a short joke (a good one) on Hart, and then things got ugly ... and hysterical!