The 31-year-old southpaw dominated all 12 rounds against his bigger Mexican opponent at Cowboys Stadium to land an eighth world title in an unprecedented eighth weight class.
Having already established himself as one of the best offensive fighters of all time, Pacquiao outclassed Margarito with his lightning hand speed and precise punching to improve his career record to 52-3-2 with 38 knockouts.
“It’s hard,” Pacquiao said ringside after winning his 13th consecutive fight since losing to Erik Morales in Las Vegas in March 2005. “I really do my best to win the fight.
“He’s strong. I never expected him to be as strong as he was. He’s a very tough fighter. I can’t believe he took all those punches.”
The Filipino, a heavily odds-on favorite going into the fight, pummelled the Mexican’s head virtually at will for much of the bout, leaving his opponent with a badly swollen right eye and a puffed left eye.
Despite being outweighed by 17 pounds, Pacquiao blended raw power with speed to deliver a dominant performance against an opponent who was also five inches taller. At one point during the 11th round, Pacquiao looked at referee Laurence Cole and asked him to stop the fight.
“I feel for my opponent, his eyes and his bloody face,” the Filipino said. “I wanted the ref to look at that.
“In the 12th round I wasn’t looking for a knockout. I take it easy because my trainer told me to take it easy and just be careful.”
One-sided verdicts
Pacquiao, fighting for the first time since winning a seat in his country’s national congress earlier this year, gained one-sided verdicts from all three judges — 120-109, 118-110 and 119-109.
“We didn’t lose a round,” said Pacquiao’s trainer, Freddie Roach. “I wish they had stopped the fight. They probably ruined his (Margarito’s) career by not stopping the fight.”
Three-times world champion Margarito, back in the ring for the first time in the United States since he lost to American Shane Mosley in a WBC welterweight title bout in January 2009, slipped to (38-7, 27 KOs).
“We knew Manny was very fast,” the Mexican said, speaking through an interpreter. “We were going good until I got caught, and then that’s when the problems started coming.”
Asked whether he had considered retiring before the end of the 12th round, Margarito replied: “No, no way. I’m a Mexican and we fight until the end. This time I failed Mexico but we will fight to the end.”
The controversial Mexican was welcomed by a mixture of cheers and boos when he first made his way toward the ring set up in the state-of-the-art home venue for the Dallas Cowboys NFL team.
Margarito and his trainer Javier Capetillo were banned for a year after plaster-like bandage wraps were found in the fighter’s gloves before the Mosley fight.
Dubbed the ‘Tijuana Tornado’, Margarito last fought in May when he beat Roberto Garcia in a WBC international light-middleweight bout in his homeland.