Open workouts are supposed to be pretty run-of-the-mill affairs. For the benefit of fans and media, the UFC trots out the fighters on a looming UFC event, has them do a light workout and break a sweat, and then hold a Q & A session. There have been a million of them, and if you’ve seen one, you’ve seen them all.

Except for today. Today, at the UFC on FOX 18 open workouts at the UFC Gym in Hoboken, N.J., former UFC heavyweight champ Josh Barnett – who will be taking on fellow veteran Ben Rothwell on Saturday in Newark – was hitting the pads with his coach, banging away with combinations, when the unexpected happened.

He was attacked by a masked assailant.

The interloper, wearing the mask of a luchador, jumped into the ring and began banging Barnett up, delivering chops to his throat, throwing him into the turnbuckle in the corner, stomping on his neck, and at one point holding Barnett in a bulldog choke.

Thankfully, Barnett, who is considered the foremost authority on competition-effective catch-as-catch-can wrestling, rallied, and eventually he turned the table on the mystery man. After dishing out a bit more punishment than he had received, Barnett was victorious, and his assailant exited the ring with his tail between his legs.

Watch the video below. I have no clue how Barnett will fare against Rothwell on Saturday, but I do know Barnett isn’t one to be trifled with when it comes to dastardly sneak attacks.