Blocker became a professional boxer in 1982. He lost his first opportunity to win a title in 1987 to
Lloyd Honeyghan. In 1990 he captured the
lineal and WBC welterweight titles from
Marlon Starling, but lost them during his next fight to
Simon Brown. In 1991 he defeated
Glenwood Brown to capture the vacant
IBF welterweight title. He defended the title successfully once against Luis Garcia. In 1993 moved up a weight class to fight
Terry Norris for the WBC light middleweight title, he was TKO'd. Later that year took on
Félix Trinidad to defend his IBF welterweight title but was KO'd in the 2nd. He retired in 1995. ==Professional boxing record==