It was the 66th fight of Pacquiao’s career, and his first since the “Fight of the Century” last May, which he lost to Floyd Mayweather.
This time the 37 year-old needed to win, if he was to crown his illustrious career in style.
"It's really important for me to win this fight, to win convincingly. It’s part of my legacy," he said before the match.
He had already lost to Bradley four years ago, when the American won by a controversial split decision, but "Pacman" reasserted his authority with a clear victory two years later.
Once again, the Filipino dominated the match in spectacular fashion on Saturday, winning his final bout by unanimous decision.
A clear victory for Pacquiao
The outcome at the MGM Grand Garden Arena reflected Pacquiao’s impressive record in the non-title welterweight duel, as the eight-division champion won by margins of 116-110 on all three of the judges’ scorecards.
Pacquiao put on an explosive performance for long periods, overwhelming Bradley with some trademark combinations.
The first round was marked by tactical precaution, with Bradley and Pacquiao both keeping at a safe distance. But the Filipino was more aggressive from the start, throwing 33 punches to Bradley's 19.
The pressure mounted in the next three rounds, as Pacquiao continued to stalk his opponent, cut off angles, and deliver some more powerful blows.
In the second round he landied a straight left on Bradley’s chin.
"He's just very quick, very explosive"
Bradley regained confidence in the fifth, but Pacquiao undid his efforts in the final minute, when he unleashed a fierce combination.
Bradley’s trainer Teddy Atlas hardly concealed his disappointment, as he yelled at his weary fighter: "Are you kidding me?"
But non of coach's admonishments could turn things around for the 32-American, as Pacquiao took the sixth round with a series of powerful counter-punches.
In the seventh, Pacquiao scored a knockdown, as he sent Bradley crashing to the canvas with a right hook to the chin.
Bradley responded with spirit, wobbling Pacquiao in the eighth round with a left hook and backing up the superstar relentlessly.
But Pacquiao bounced back in emphatic fashion, luring in Bradley before delivering a deadly left hook. A second left hook sent his rival down once again, leaving Pacquiao with a commanding lead heading into the final three rounds.
The Filipino paid tribute to his American rival: "Bradley is a good boxer, he's a champion, he's a man. It was not easy tonight."
The defeated 32 year-old reacted with equal humility.
"He's just very quick, very explosive," he said. "I'm in there with a special man, Manny Pacquiao."
After the match the two fighters embraced in the ring, and arranged to meet for breakfast on Sunday.
A moving farewell
Pacquiao has insisted this was his final fight before he focuses on his political career in the Philippines, where he is seeking election to the Senate next month. But many ring-watchers still believe he might return one day.
When after the match he was asked if he planned to stay retired, Pacquiao replied: "I think so. I've made a commitment to my family that I'm going to retire after this.”
"Maybe I enjoy being a retired man, serving the people, helping the people," he added.
Meanwhile in Philippines, the news of Pacquiao's final victory was met with a mixture of pride and sorrow.
The fight was screened in public plazas and stadiums, so crowds of admirers could watch their national hero one last time.
Throughout the impoverished nation, Pacquiao's rags-to-riches story has been an inspiration for millions of people.
President Benigno Aquino also intervened, saying via his spokesman that the boxer had done the nation proud.
With his mind at rest following his final victory in the ring, Pacquiao can now turn to his new challenge: to gain a seat in the powerful Senate, under the banner of the opposition UNA party.