Well that's a first...
We've all seen the streakers at baseball games, but at a cage fight? That guy has some balls! (I've seen them.)
The incident happened back in 2006 when Alexandre Izidro and Mario Stapel were competing for the lightweight title at Cage Warriors Fighting Championship – Strike Force 6.
The fully nude (except for those black socks) man hopped over the cage and fell onto the mat just feet away from where the two athletes were engaged in some heavy grappling. The judge paused the fight until the streaker was removed but not before Izidro and Stapel sat back and laughed at the predicament they were in. I don't know how they continued to fight after that.
But they did, and went the full five rounds to boot!
Izidro would go on to defeat Stapel by majority decision.