by Edward Chaykovsky

USF Sundome, Tampa, Florida - In the main event of the Premier Boxing Champions debut on ESPN, Keith Thurman (26-0, 22KOs) retained his

WBA 'regular' welterweight championship with an eight round stoppage of

former beltholder Luis Collazo (36-7, 19KOs).

Thurman had some adversity in the fifth round, when he was severely hurt by a hook to the body. The punch came in the final minute of the round and he was able  to use his legs to get out of trouble. Both of Collazo's eyes were swelling up as the fight progressed and he was cut above the right eye.

Prior to the official start of the eight, Collazo said he couldn't see out of his right eye and the fight was waved off.

Thurman then, once again, called for a fight with WBC/WBA full welterweight champion Floyd Mayweather Jr. (48-0, 26KOs). The Mayweather camp has already ruled out Thurman as a potential opponent for their scheduled return on September 12th at the MGM Grand in Las Vegas.

“I’m a young, strong champion, Floyd, come get it,” Thurman said. “I’m undefeated like you, baby, come take my ‘0,’ baby. I’m ready.”