In 2005 Williams outpointed former Olympic bronze medalist Terrence Cauthen, and later that year, he knocked out Alfonso Sanchez in 5 rounds. His ESPN debut was a second round knockout of Sergio Rios on Wednesday Night Fights. Williams made his HBO debut against undefeated Walter Matthysse, winning by a tenth round technical knockout. That victory was followed by a victory over former junior welterweight world champion Sharmba Mitchell. He knocked Mitchell down three times en route to a fourth round TKO.
Williams became the mandatory challenger for WBO welterweight champion Antonio Margarito. The match took place July 14, 2007, in Carson, California, at the Home Depot Center with Williams winning a unanimous decision. However, Williams fought Carlos Quintana on February 9, 2008 in his first defense of his title and lost by decision.
Williams and Quintana rematched on June 7, 2008 for the WBO welterweight title. Williams got off to a quick start when a left hand sent Quintana into a daze as several follow-up barrages put Quintana down. He got up, but Williams opened up with dozens of unanswered punches as the referee jumped in to stop the fight while Quintana was going down again.
After failing to secure another meaningful contest at welterweight, Williams vacated his WBO welterweight title in order to fight Verno Phillips for the WBO Interim Junior Middleweight title.
On November 29, 2008, Williams defeated Phillips by way of TKO after 8 rounds after the Doctor stopped the fight. In doing so he secured the WBO interim junior middleweight title.
Williams fought Winky Wright on April 11, 2009, in a 12-round middleweight bout featured on HBOm easily outpointing Wright to cruise to a lopsided unanimous decision. Williams was then preparing to fight middleweight champion Kelly Pavlik in a bout scheduled to take place on October 3, 2009 in Atlantic City but the bout was eventually cancelled when it was discovered Pavlik had a staph infection.
Bouts with Sergio Martínez
In a blazing contest that saw both men hit the canvas, Williams defeated Sergio Martinez via a close, majority decision on December 5, 2009. Afterward, both fighters expressed interest in a possible rematch that eventually materialized in November 2010. Upon Williams's insistence, the fight was contested at the catchweight limit of 158 pounds instead of the middleweight limit of 160 with Martinez's WBC Middlweight title on the line. The fight was billed as a potential "fight-of-the-year," however the fight ended abruptly and dramatically when Sergio Martinez delivered a knockout blow in the 2nd round that caught Williams right on the chin, as he attempted to deliver a left-hand of his own. Williams was unconscious upon contact.
Throws punches in bunches
Very high activity rate
Long reach (82")
The 'Punisher's' debut was in 2000
Williams is promoted by the Goossens
Major World Titles
TD 4 Kermit Cintron - 2010
MD 12 Sergio Martinez - 2009
UD 12 Winky Wright - 2009
TKO 1 Carlos Quintana - 2008
UD 12 Antonio Margarito - 2007
KO 4 Sharmba Mitchell - 2006
KO 2 Sergio Martinez - 2010
UD 12 Carlos Quintana - 2008