It's official. After negotiations between he and Manny Pacquiao failed, Floyd Mayweather is moving on to his next fight -- a bout against "Sugar" Shane Mosley.

Mayweather officially signed the contract this week to face Mosley on May 1st in Las Vegas.

"This one is definitely for the fans, as I wasn't going to waste anyone's time with a meaningless tune-up bout and asked to fight Shane immediately," said Mayweather. "I have said ever since I came back to the sport that I only wanted to fight the best I think Shane is one of the best, but come May 1, he still won't be great enough to beat me."

"I have always wanted to fight Floyd and now it is finally coming true," added Mosley. "I am already in great shape and ready to show everyone on May 1 that I am stronger, faster and better than he is. I will have no problem beating him."

One condition of the upcoming bout is that both fighters take Olympic-style drug testing leading up to the fight, the same test that caused all the controversy during negotiations with Pacquiao's camp.

Maybe a slap in the face for Pacquiao?

"He can't wait to extend his undefeated record and perform at the highest level," said Leonard Ellerbe, CEO, Mayweather Promotions. "More importantly, he is also happy to set the precedent for random blood testing in order to ensure fair and safe contests for all fighters."

"Shane Mosley is one of the greatest fighters of this era and I commend him for not only agreeing to the fight against Mayweather, but also agreeing to participate in a testing process that can only help the integrity of the sport," added Richard Schaefer, CEO, Golden Boy Promotions.

Mayweather was a 1996 Olympic Bronze medalist for the U.S., who has since gone on to strike gold in the professional ranks, winning six world titles in five weight classes to firmly establish himself as one of the most elite fighters of his era. He's destroyed some of the sport's most decorated fighters -- including Diego Corrales, Jose Luis Castillo, Arturo Gatti, Zab Judah, Oscar de la Hoya and Ricky Hatton.

He retired in 2008, but left the door open for a return. After an 18-month layoff, he returned to boxing with a dominating victory over future Hall of Famer, Juan Manuel Marquez.

Future Hall of Famer Shane Mosley has five world titles to his name -- and has ruled the lightweight, welterweight and junior middleweight divisions over his storied 16-year career. At 38 years old, California native just seems to get better as the years pass. He's won seven of his last eight fights dating back to 2005 -- defeating the likes of Fernando Vargas (twice), Luis Collazo and Ricardo Mayorga, but his most recent victory -- a ninth round stoppage of Antonio Margarito in January 2009 -- was one of his most spectacular. The win earned him the welterweight world title for the third time.

Ticket info, prices and more info will be announced soon.