By Edward Chaykovsky

In what he says will be the final fight of his 19-year career, pound-for-pound king Floyd "Money" Mayweather (48-0, 26 KOs) is not taking any chances against former WBC/IBF welterweight champion Andre Berto (30-3, 23 KOs) on Saturday, Sept. 12 at the MGM Grand Garden Arena in Las Vegas, live on SHOWTIME PPV (8 p.m. ET/5 p.m. PT).

Mayweather will take his WBC/WBA world titles against a man who almost everyone views as a huge underdog.

Berto has gone 3-3 in his last six outings. Back in March, Berto knocked out Josesito Lopez in six rounds.

When Mayweather named Berto as a possible opponent in June, everyone thought he was joking to hide the name of the actual opponent.

Mayweather is not taking Berto as a joke.

"I'm ready to get back in the ring on September 12 and prove again to the whole world why I'm 'The Best Ever,'" said Mayweather. "I always bring my A-game and this fight against Andre Berto is no exception. He's a young, strong fighter who is hungry to take down the best. Forty-eight have tried before and on September 12, I'm going to make it 49."

Leonard Ellerbe, CEO for Mayweather Promotions and personal adviser to Floyd, says the entire arsenal of skills will be needed to defeat Berto. 

Money' Mayweather is back and the whole Mayweather Promotions team is ready to build off of the incredible record-breaking May 2 event," said Ellerbe. "It's a pleasure to bring this great fight, plus the incredible undercard of action, to the fans in Las Vegas at MGM Grand. Andre Berto is a powerful fighter who presents a real danger to Floyd.  He will have to use all of his skills to slow Berto down."