The 32-year-old southpaw received as much punishment from his older opponent as he dished out over the 12 rounds but his superior foot and hand speed made the difference as he improved his career record to 54-3-2 with 38 knockouts.
Back in the ring for a third time since claiming a seat in his country’s national congress last year, Pacquiao won his 15th consecutive fight after earning two of the verdicts from the three judges.
Dave Moretti (115-113) and Glenn Trowbridge (116-112) awarded the fight to the Filipino while Robert Hoyle made it a 114-114 draw.
“My fans are very happy because clearly they thought I won the fight,” Pacquiao said in a ringside interview as boos echoed around the arena from the disgruntled Mexican fans.
“We have to accept that my opponent is not easy. He is a good fighter and it’s not easy, but I won the fight. He was ready for my punches but I thought I blocked a lot of his punches.”
Asked if he would consider a fourth bout with three-division world champion Marquez who has consistently been his toughest opponent, Pacquiao replied: “Anytime, anytime. I am a fighter and my job is to fight in the ring.”
Marquez, who lifted his arms in triumph after the fight ended, was bitterly disappointed with the outcome after firmly believing he had been cheated of victory in his two previous meetings with Pacquiao.
“It’s hard when you’re fighting your rival and the three judges, too,” the 38-year-old Mexican said in his dressing room, having stormed out of the ring after the decision was announced and his chance of vindication denied.
“I got robbed. Honestly I don’t know what I need to do to change the mind of the judges. We won with clearer punches. I am frustrated right now, very frustrated.”
The two boxers, renowned for their aggressive approach in the ring, fought to a draw in May 2004 before Marquez lost his WBC super-featherweight title to Pacquiao in a controversial one-point split decision in March 2008.
Watched by a sell-out crowd of 16,368 that included former heavyweight champion Mike Tyson, Pacquiao initially focused on his lightning left jab in the opening round while Marquez relied on counter-punching.
The nimble-footed Filipino, moving faster than his opponent, dictated the early pace but Marquez caught Pacquiao with a couple of right-hand body blows in the second round.
An evenly matched third round ended after Paquiao struck Marquez in the head with a crunching right hook and both boxers traded a flurry of telling counter punches late in the fourth.
As chants of “Marquez, Marquez, Marquez” echoed around the arena, the Mexican dominated the fifth round, catching Pacquiao with a searing left uppercut to the head and later on with a crunching right.
With the intensity building, the two fighters counter-punched at every opportunity and Marquez had the better of the seventh round, landing solid lefts and rights with pinpoint accuracy and cutting Pacquiao on the lip.
The Filipino upped his work rate in the ninth round, peppering Marquez with a series of combinations to the body and head while varying his angle of attack with slick foot movement.
Pacquiao, who has won world titles in an unprecedented eight weight divisions, was cut above the right eye in the 10th but immediately signalled to referee Tony Weeks that he had been head-butted and went on to finish the round with a flurry of solid punches.
The two fighters strived to claim a telling advantage in the last two rounds, though Pacquiao landed a crunching left to the Mexican’s head late on in the 12th.
The official statistics reflected how closely Marquez challenged Pacquiao.
He connected with a higher percentage of punches thrown, 138 of 436 to the 176 of 578 for the Filipino, and landed 100 power punches compared to his opponent’s 117.
Earlier on Saturday, American Timothy Bradley retained his WBO junior welterweight title by stopping Cuba’s Joel Casamayor in the eighth round of a lopsided bout.
