Pacquiao (56-5-2) pursued and peppered the previously unbeaten Bradley around the MGM Grand Garden ring with an aggressive performance recalling the Pacman in his prime. Bradley fought back with counterpunching and elusiveness, but Pacquiao kept up his attack while Bradley (31-1) struggled down the stretch.
Pacquiao left little doubt about the result of the rematch in the same arena where they met nearly two years ago. Bradley's split-decision victory astonished most ringside observers, who felt Pacquiao had earned a clear decision.
Judges Craig Metcalfe and Michael Pernick scored the rematch 116-112 for Pacquiao, while Glenn Trowbridge favoured the Filipino congressman 118-110. The Associated Press scored it 116-112 for Pacquiao.
After the fight, Bradley said he injured his right calf early on. But he also applauded the decision when it was announced, and he congratulated Pacquiao in the ring.
"You won the fight, you deserved the win," Bradley said. "I have no excuses."
Pacquiao landed 35 per cent of his 563 punches, while Bradley connected with just 22 per cent of his 627 blow. Pacquiao's jab was much more effective, landing 23 per cent to Bradley's measly 11 per cent, and the Pacman had a slight edge in landing 148 power punches to Bradley's 109.
Pacquiao's performance righted one of the biggest perceived wrongs in recent boxing history. Pacquiao was an eight-division world champion on 15-fight winning streak when Bradley was awarded a split decision in their last bout.
Pacquiao was more aggressive and accurate from the opening minutes of the rematch, sticking to trainer Freddie Roach's pleas to take the action to Bradley. They exchanged big shots in the opening rounds, but Pacquiao appeared to wear out Bradley with the heavy early pace — and the Pacman never slowed down.
Although Pacquiao couldn't knock down Bradley, he answered the questions raised by Bradley about his killer instinct with a consistent attack all night.
The arena was crackling with energy when both fighters made their ring walks, with Pacquiao in the unusual position of going first as the challenger.
Pacquiao landed a series of big left hands in the early rounds, knocking back Bradley with gusto. Bradley responded impressively in the fourth round, wobbling Pacquiao twice with a right hand.
The pace slowed in the fifth, with Bradley showing off his defence and movement while Pacquiao attempted to trap him against the ropes.
Pacquiao appeared to wobble Bradley late in the seventh round with a vicious combination, but Bradley stood with his back against the ropes and defiantly encouraged it, blocking most of the shots. Bradley appeared to pretend to have wobbly legs at one point after a Pacquiao miss, but his open mouth betrayed his weariness while Pacquiao steadily racked up rounds midway through the fight.
Bradley came on strong in the 12th, and the fighters' heads collided late in the round. Pacquiao avoided any trouble until the final bell, when he did a short dance step to his corner.
While Bradley remains publicly confident he beat Pacquiao in their first bout despite fighting on two injured feet, that much-derided decision sent both fighters' careers on wild spirals.
The two judges who scored the bout 115-113 for Bradley are no longer in the boxing business, but their decision ended Pacquiao's 15-fight win streak and forced Bradley to defend himself against widespread criticism of the result.
Bradley endured death threats and depression before returning to the ring in unusually reckless style. He brawled with Ruslan Provodnikov in March 2013 in a sensational unanimous-decision victory that silenced critics of his style and heart. Bradley then outpointed veteran Mexican champion Juan Manuel Marquez last fall, polishing his skills and making himself attractive to Pacquiao for a rematch.
Pacquiao was knocked unconscious by Marquez in the sixth round of their fourth fight in late 2012, and he took nearly a year off before returning for an unspectacular victory over Brandon Rios last fall. Pacquiao's last two performances prompted Bradley to declare Pacquiao had lost his killer instinct, noting he was unable or unwilling to stop any of his opponents since late 2009.