After months of trash talking each other, Conor McGregor finally went toe-to-toe with a boxer on Thursday night.No, they didn't reschedule the McGregor-Floyd Mayweather epic without you realising. This time, it was Paulie Malignaggi.Malignaggi, who actually retired from boxing earlier this year, finally took up McGregor's sparring challenge at his gym in Las Vegas.The UFC star posted an image on Twitter from the session which showed him in typically confident spirits - posing with his hands behind his back.Like most of McGregor's posts, it went viral and some fans suspected this was a sign he could actually pull off one of the biggest upsets in boxing history and beat Mayweather.Malignaggi also took to Twitter after the session but refused to give away any specific details from the session.
However, he has since spoken in an interview with ESPN to reveal how McGregor fared up against him.
And Malignaggi admitted he enjoyed facing the two-weight UFC champion.
"There was a lot of trash talking right away, which me and him both known to have a little bit. Like I said, we did eight good rounds of work. It was physical work and Conor is coming along." Malignaggi said.
"A lot of fighting right away. At the end, you look back on it, it was kind of fun. I don't have many people who can match my trash talk, but Conor definitely can. It was making it a lot of fun.
The American will stay on as one of McGregor's sparring partners in the build up to the fight.
If McGregor is to have any success against Mayweather it is thought his left hand could be the key.
And after feeling the force of the Irishman's big weapon, Malignaggi thinks it would be foolish to rely upon that alone.
He added: "He's got some pop in the left hand, I can't take that away from him.
"In boxing, especially against a guy like Floyd Mayweather, you need to devise a few more weapons, and I think that's what Conor is working on.
"I think... coming into this situation already knowing Conor has a big left hand... you're probably going to prepare for that left hand."
"Obviously, Conor is working on other things besides the left hand, so there can be that surprise element to it.
"There's going to be other things he needs to make you worry about, and that's what's being worked on in camp. He's effective at what he's doing."
But does Malignaggi actually think his sparring partner has a realistic chance of beating the unbeaten Mayweather?
"I think [McGregor] is definitively an underdog, but he has a method to what he's doing and he has a thinking process behind it," Malignaggi continued.
"This is a fight of moments, and I think he can give himself certain moments.
"If those moments turn into bigger moments, that's not up to me. That's up to Conor McGregor."