Justin Bieber has made a Belieber out of Mike Tyson!

The unlikely duo bonded when Bieber stopped by Tyson's home for a boxing lesson. 

"Justin swung by my place during the weekend of the Billboard Music Awards to say hi to the family," Tyson, 45, wrote on his YouTube page with a video of Bieber, 18, boxing. "We took him straight to garage and had him hit the bags. JB's got the moves!"

And the heavyweight champion of the world also tweeted photos of Bieber's visit from the weekend of May 20. "Me, John Shahidi and Justin Bieber before we started training JB," he captioned a photo Sunday of their fierce pose in the gym.

But the "Boyfriend" singer also spent time with Tyson's kids. "Hanging out with JB and the kids last weekend," the boxer wrote with a photo of Bieber playing on a couch with his seven children.

In return for the boxing lesson, Bieber gave Tyson a taste of his new music from his upcoming album, Believe.

"I got to hear a song JB did with my man Rodney Jerkins and it was awesome," Tyson tweeted. "I can't wait to hear more."

Believe is set for release June 19.