Former UFC heavyweight Shane Carwin KO’s Jason Ellis with one arm

Shane Carwin’s devastating knockout power hasn’t diminished in the slightest. Carwin, who retired from mixed martial arts due to a series of injuries in 2013, made his return on Saturday at EllisMania 13, an event hosted by professional skateboarder and radio host Jason Ellis.

Carwin took on Ellis is an exhibition boxing match in the main event, where the former UFC interim heavyweight champion agreed to duct tape his right arm to his side. That didn’t stop the 41-year-old from brutally KO’ing Ellis with a lead left hook in the second round, earning his first knockout in six years.

Carwin became known as one of the pound-for-pound heaviest hitting fighters in the sport, and holds devastating knockout wins over Frank Mir and Gabriel Gonzaga. The Colorado native perhaps became most known for his first round drubbing of Brock Lesnar at UFC 116, where he battered the heavyweight champion for five minutes before succumbing to exhaustion — and an arm-triangle choke — in the second round.

Ellis, 45, has previous experience in combat sports. The former Team Quest member submitted Tony Gianopulos in 2009 and holds two exhibition wins over Gabe Ruediger, a former contestant on series 5 of The Ultimate Fighter.