MARK RUFFALO, who’s topped a solid career by shooting to superstardom as the Hulk in “The Avengers,” wined, dined and reminisced with pals at chi-chi Chateau Marmont about working there back in the day – then gave them a blast from the past!

Said My Marmont Spy: “Mark asked the manager to let him wait on tables for old times’ sake. Moments later, he emerged from the kitchen juggling two armloads of plates and started serving guests.”

Mark wasn’t recognized until a lady complained she’d ordered fries instead of mashed – and his body abruptly expanded, bursting out of his clothes!

Flexing huge, green muscles, he roared: “Hulk no like puny humans… Hulk SMASH!” (Oh, I’m kidding!)

Actually, Mark served very professionally, returned to his table and told pals: “I love going back in time. It keeps me humble – and makes me realize how lucky I really am!”