Kanye West

A video has just surfaced showing a man purported to be Kanye West fist fighting like a champion ... knocking 2 guys out cold. If it's Kanye it could be disastrous in his upcoming criminal case because prosecutors want to show he's violent by nature -- HOWEVER....

TMZ has confirmed ... the fighter is NOT Kanye. The video was shot in Austin, TX and Mr. Kardashian wasn't there at the time.

Our Kanye sources say he's aware of the video and laughed, saying if it were really him, he'd be in jail for sure.

All that aside, you gotta see this video. It's awesome.