Erik Morales made history, though it came at Timothy Bradley's expense.
Morales on Saturday became the first Mexican fighter to win world titles in four weight divisions, scoring a 10-round technical knockout over Pablo Cesar Cano to capture the vacant WBC junior welterweight belt at the MGM Grand Garden.
The fight was on the undercard of the Floyd Mayweather Jr.-Victor Ortiz welterweight championship fight.
Morales (52-7) won the title formerly held by Bradley, who in July was stripped of the belt by the WBC for his refusal to fight while involved in a legal dispute with his promoter. Bradley hasn't fought since January, when he beat Devon Alexander.
"I'm really happy about the fourth title, but it was more difficult than I thought it would be," Morales said. "It took me some time to get my rhythm, but I did and was the better fighter."
Morales originally was scheduled to fight Lucas Matthysse, but he dropped out two weeks ago because of a viral infection. The WBC inserted Cano, who fell to 22-1-1, as his replacement.
Morales opened a cut over Cano's left eye in the third round, and it got progressively worse. Morales' jab was effective, and when he began to land combinations, Cano struggled to answer.
"I could tell the blood was making him nervous, and when he started bleeding profusely, I could tell he was scared," Morales said.
At the end of the 10th round, Dr. Al Capanna told referee Kenny Bayless that Cano was not fit to continue and the fight was stopped. Morales was ahead 97-93 and 96-94 on two of the three judges' scorecards, the other having it 95-95
"I'm disappointed with the way it ended," Cano said. "The cut definitely affected me. I think I would have finished 12 rounds had I not been cut."
Also on the undercard, Las Vegas junior welterweight Jessie Vargas improved to 17-0 with a 10-round split decision over Josesito Lopez.
Vargas, a Palo Verde High School graduate, looked good at times, though Lopez appeared to land the more effective punches. The scores were 96-93 and 95-94 for Vargas and 95-94 for Lopez.
"I think it was a good decision," Vargas said. "He was a hell of a fighter and I give him all respect. I was surprised he could take the power of my punches."
Also as part of the undercard, Saul "Canelo" Alvarez retained his WBC super welterweight title with a sixth-round TKO of Alfonso Gomez at Staples Center in Los Angeles.
Alvarez knocked down Gomez in the first round. In the sixth, Alzarez rocked him with a huge right uppercut and followed with a series of blows that had Gomez reeling. Referee Wayne Hedgepeth stopped the fight at 2:36.