Here's a painful lesson on why you should NEVER get in a street fight -- courtesy of UFC star "Platinum" Mike Perry.
We asked Platinum -- who fights this weekend at UFC on FOX 26 -- to give us the lowdown on if he's ever had to throw down outside the Octagon ... and the story he hit us with was Oscar-worthy.
It all went down on a New Year's Eve in DT Orlando ... when Mike and his GF, "Platinum Princess" Danielle Nickerson, were out celebrating on the streets.
Perry says a random guy was dumb enough to hit on Danielle when they were clearly together ... and fire on Platinum after he told him to step off!
Mike says he fired back with a left hook from hell ... and you can guess how that turned out.
The whole thing's pretty hilarious. Also, kinda terrifying.