Joe Cortez had to separate Conor McGregor and Paulie Malignaggi after the pair tried to “rough each other up” during a fiery sparring session.

The well-known ref was brought in to teach UFC star McGregor the rules of boxing ahead of his superfight with Floyd Mayweather. But he ended up acting as peacemaker when McGregor and Malignaggi got heated in the ring.

Cortez said both fighters started off firing verbal shots at each other – leading the session off the rails.

“It was the real thing, I had to stop the action, say, ‘You guys are a little out of control here, you’ve got to stop this.’ You know, they got a little rough,” Cortez said on Sirius XM Rush. “They were both roughing each other up and I had to stop the action like it was a regular fight. They were holding too much – they were trying to punch each other.

“So I had to call, ‘Time, alright guys you’ve got to stop this right now, I want a good, clean, strong – give me a sportsman-like conduct you understand?’”

McGregor called out Malignaggi after the American claimed last year that the MMA fighter was being disrespectful to the sport of boxing by wanting to fight Mayweather.

“Yeah, look, Paulie talked a lot of s–t,” McGregor said. “Look he’s been brought in to spar and then he’ll answer to what he’s been saying and then we’ll go from there after that. But we’re gonna have a knock in the gym. I mean, look, we’re going have a knock and he’s gonna have to answer to what he’s been saying.”