Whatcha gonna do, brother ... when O'CONNELLMANIA runs wild on you?!?!?
Yep, Jerry O'Connell stepped right into the squared circle at the Rumble of the North event in Canada this weekend ... where Carter "King of the North" Mason was battling Travis McCabe.
O'Connell was the special "guest referee" -- but when McCabe called him out in the center of the ring, Jerry ditched the stripes and went full beast mode!!!
Fun Fact -- Jerry's JACKED!!!
Also, he totally screwed over McCabe to help Mason win the match.
Dirty tactic ... but effective.