Pacquiao won on two scorecards, while the third ringside judge had it a draw. It was a narrow escape for the Filipino congressman, who took as much punishment as he got over 12 rounds.
The third fight between the two was as close as the previous two, and by the time they finished 12 arounds the outcome was still in doubt. Pacquiao won some rounds with sheer agression, while Marquez won others with brilliant counterpunching, keeping Pacquiao from getting inside.
Marquez was a 7-1 underdog, but it was clear early he would be in this fight. He picked Pacquiao apart with right hands almost every time he tried to get inside, and landed good hard flurries throughout the fight.
Pacquiao was the aggressor throughout, and landed some sharp punches of his own. But when the decision was announced, the crowd booed roundly and, once again Marquez had lost a close fight.
One ringside judge had it a 114-114 draw, while two others favored Pacquiao by 115-113 and 116-112. The Associated Press had it 114-114.
The sellout crowd at the MGM Grand arena threw bottles and cans toward ringside after the decision was announced, with one full can hitting a ringside writer. Marquez, who had been bitter about the scoring in the first two fights, stormed out of the ring.
Pacquiao continued his remarkable run with the win, but it didn't come easy. He had trouble all night finding his range and, when he did get inside, Marquez often moved to the side and landed a counter right hand.
It was the third close fight between the two men, though this one was fought at 144 pounds instead of 125 as was their first fight seven years ago. That fight was a draw, while Pacquiao won a split decision in the second bout in 2008 at 130 pounds.
"My fans are very happy because they thought I won," Pacquiao said when asked about the crowd reaction.
Marquez fought going backward all night, and that might have been his undoing. While he landed well at times, Pacquiao was in his face most of the night.
"I got robbed," Marquez said. "I don't know what else I can do to win."
Pacquiao earned a minimum $22 million for the fight, while Marquez got $5 million.