Chief Keef took a leap onstage that turned into him taking a huge dive offstage ... and coming dangerously close to busting his ass and his head.
If not for the speedy reflexes of a dude working security, Keef would be in a hospital right now. As it is he survived to finish his show in Detroit Thursday night.
The bad news for the rapper is ... if he didn't get his ass on a jet right after the show he could be in big legal trouble. Keef's supposed to be in an L.A. courtroom Friday morning -- he's being arraigned robbery and assault charges for allegedly attacking a producer.
It's a felony, so he's gotta be there. If Keef misses the court date, he might wish he'd taken the dive -- at least he'd have a doctor's note.