Leonardo DiCaprio -- Manhandled like a Bitch ... At Coachella

Forget dancing lessons, Leonardo DiCaprio needs SPARRING lessons -- because his friend made easy work of him during a play fight at Coachella this weekend ... and the video is hilarious.

Leo was hanging with friends at Diddy's Revolt party Sunday -- we're told the boys got rowdy and somehow Leo ended up locking horns with a friend ... a friend who happens to have a background in MMA.

It's harmless roughhousing -- but Leo never stood a chance. He's lucky his friend didn't pull the "stop hitting yourself" thing.