Spotted: Justin Bieber in Boxing Champ Floyd Mayweather's Corner

Singer Justin Bieber holds up a belt for Floyd Mayweather Jr. before Mayweather Jr. takes on Miguel Cotto during their WBA super welterweight title fight at the MGM Grand Garden Arena on May 5, 2012 in Las Vegas, Nevada. (Source: Al Bello/Getty Images North America) more pics » Justin Bieber and 50 Cent enter the Mayweather vs. Cotto fight  (Al Bello/Getty Images North America) Justin Bieber is a big deal to millions of teenage girls, but he apparently also has a fan in boxing superstar Floyd Mayweather. The teen singer got to hang out in the welterweight champion's corner at his title fight in Las Vegas Saturday night, an invitation that's surely hard to come by. Perhaps Mayweather is a big fan of "Baby."

Bieber had two giant title belts wrapped around his shoulders as he entered the MGM Garden Arena with rap star 50 Cent. Then he anxiously watched Mayweather take on Miguel Cotto with more of the boxing champ's entourage.

Mayweather remained undefeated, racking up his 43rd victory, and, of course, the Biebs made it into the pictures following the match. The singer and his new hairstyle posed next to Lil Wayne and the champ before calling it a night. We have a feeling Mr. Wayne and the guys hit the town to celebrate, but Bieber has a few more years to go before he's able to enjoy the Vegas club scene.

Bieber had to get some beauty sleep anyway: "in and out of vegas for the fight. now back for rehearsals tomorrow. goodnight world. hard work and dedication," he tweeted.

Worth noting: It's unclear how Bieber knows Mayweather. But, the singer did compare himself to the athlete in an interview back in January. "Now that I'm on top, everyone wants to bring me down. Everyone's trying to tug at me and take my spot," he said. "Like Floyd Mayweather, he's the best boxer in the world. Now he is a champion. Every time he goes to a fight now, people are like, 'He's going to lose this time'."

Bieber also claimed he's a "pretty good boxer."

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