Las Vegas - Filipino star Manny Pacquiao edged Juan Manuel Marquez by majority decision on Saturday, stretching his win streak to 15 fights but leaving his Mexican foe screaming robbery for a third time.
Adding more controversy to an already-heated rivalry, two judges handed Pacquiao the 12-round victory by margins of 116-112 and 115-113 while the third scored the fight a 114-114 draw.
"It was clear to me that I won," Pacquiao said. "I clearly won."
Marquez was already seething before the latest loss, saying he had beaten Pacquiao in a 2004 fight that was called a draw and a 2008 rematch in which went to the Asian southpaw by one point on one judge's scorecard.
"It was a robbery. They robbed me again," Marquez said. "I'm really, really frustrated. I don't know what I have to do for the judges to win this fight.
"It's hard when you're fighting your rival and three judges too."
This defeat was so bitter, Marquez said he was pondering retirement.
"The result of this fight has me thinking of retirement," he said. "This fight was the biggest of my career. I prepared so hard. We wanted the judges to score this fight the way it happened, not how they scored it."
After the 12th round ended, Marquez raised his right hand in a sign of victory while Pacquiao simply trudged back to his corner with a downward gaze, only for both men to learn moments later that the verdict was another story.
"I was preparing for somebody in my corner to raise me and take me around the ring," Marquez said. "But I was surprised again, surprised by the judges."
Pacquiao, who has not lost since 2005, improved to 54-3 with two drawn and kept his World Boxing Organization welterweight title while Marquez fell to 53-6 with one drawn.
"This was a robbery of the utmost," said Marquez's trainer, Ignacio Beristain. "I'm very frustrated. Decisions like this are a joke. I'm disappointed. The real winner was Juan Manuel Marquez, not Manny Pacquiao."
A lot of people agreed.
The result was greeted with a chorus of boos from Marquez supporters, some of whom tossed cans and bottles at the ring after a fight that had most of the crowd standing and cheering during the later rounds at electrifying exchanges.
"The fans of Marquez of course are very disappointed. I understand how they feel," Pacquiao said. "But I blocked a lot of his punches. He's a counter puncher. He head-butted me a lot."
Pacquiao's promoter Bob Arum, who had a rematch clause had Marquez won, said he still would attempt to stage a fourth Pacquiao-Marquez fight in May, likely a message to unbeaten US star Floyd Mayweather that his talk of a May 5 fight with Pacquiao was merely wishful thinking.
"I'm going to try and make this rematch in May of 2012," Arum said. "I'm bound and determined to find a definitive winner once and for all."
That's fine with Pacquiao.
"I'm all for it," he said.
Marquez was less certain.
"Everybody knows what happens," he said. "I won this fight - again."
Marquez's claim that he won both prior Pacquiao fights prodded the Filipino to train with unprecedented passion and call this bout one of his most important fights, vowing to prove that he was indeed the better boxer.
Instead, it might take four to settle the score of which fighter is best.
"What can I say? It was a real close fight," Pacquiao trainer Freddie Roach said.
Had all three judges given the final round to Marquez, the fight would have ended in a draw. Instead, the only judge who did was the one who gave Pacquiao his most lopsided victory margin.
Pacquiao, a world champion in a record eight weight divisions in his career, denied Marquez a title in his fourth different weight class.
Marquez, six years older than Pacquiao at 38, began landing power punches in the fourth round, about the time "PacMan" said he began having cramps in the arches of his feet, hindering his movement and ability to evade the punches.
"I felt so bad," he said. "My balance was gone."
Marquez began connecting with powerful overhand rights to Pacquiao's head several times in the fifth round and twice in a row in the sixth. Furious toe-to-toe-exchanges in the seventh drew cheers and a standing ovation.
But Marquez only won one of the last five rounds on the scorecards of the judges who went for Pacquiao desite each of them seeming to be up for grabs.