Drake Doggin' On Diddy -- Gimme That Mic!

Drake sure has balls ... hijacking the mic from one of the founding fathers of modern hip hop during the NBA All-Star weekend.

Drake and Diddy were at Metropolitan club in New Orleans ... along with Nelly, Busta Rhymes, Kevin Hart and Fabolous ... when Drake broke out his tune, "Worst Behavior."

Diddy joined in ... and Drake pulled a Kanye on the rap mogul.