-LRB- CNN -RRB- -- Floyd Mayweather Junior has confirmed that he will fight WBA welterweight super champion Shane Mosley in Las Vegas on May 1 following the controversial collapse of his much-hyped showdown with Manny Pacquiao . The 38-year-old Mosley , a three-weight world title winner , had already signed up for the bout at the MGM Grand , which will take place under the Olympic-style random blood testing drug protocols that Pacquiao refused to accept . The undefeated Mayweather , a six-time world champion at five different weights and Pacquiao 's chief rival for the pound-for-pound bragging stakes , said in a statement that he was looking forward to taking on his fellow American . `` This one is definitely for the fans as I was n't going to waste anyone 's time with a meaningless tune-up bout and asked to fight Shane immediately , '' the 32-year-old said . `` 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 wo n't be great enough to beat me . Mosley had been due for a unification bout on January 30 with Andre Berto , who claimed the WBC title that Mayweather vacated when he retired in 2008 , but the fight was scrapped when his opponent lost family members in the Haiti earthquake . `` I have always wanted to fight Floyd , and now it is finally coming true , '' Mosley said . `` 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 . '' Mosley 's promoter Golden Boy took the chance to have a dig at Filipino star Pacquiao over his refusal to undergo blood testing in the lead-up to the planned fight with Mayweather . `` 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 , '' Golden Boy chief executive Richard Schaefer said . Leonard Ellerbe , his counterpart at Mayweather Promotions , also weighed in on the matter . `` Floyd has been trying to make this fight for the last 10 years , so he is extremely excited about the opportunity to face Shane . He ca n't wait to extend his undefeated record and perform at the highest level , '' Ellerbe said . `` 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 . '' Pacquiao will defend his WBO welterweight title against Ghana 's Joshua Clottey in Dallas on March 13 before returning to politics as he seeks election in his local constituency .