Manny Pacquiao (right) connects with a right to the face of US boxer Keith Thurman during their WBA super world welterweight title fight on Saturday in Las Vegas, Nevada. Photo: AFP

Filipino legend Manny Pacquiao rolled back the years to become the oldest welterweight champion in boxing history with a thrilling split decision victory over WBA champion Keith Thurman on ­Saturday.

The 40-year-old Pacquiao, 10 years older than the previously undefeated Thurman, delivered a vintage performance at the MGM Grand Garden Arena to leave the sell-out crowd of 14,356 roaring its approval.

Pacquiao floored Thurman with an electrifying combination in the first round and remained on the front foot throughout a pulsating 12-round duel.

Although the bloodied Thurman rallied in the later rounds to narrow Pacquiao's lead, the judges scored it in the Filipino's favor. Two judges scored it 115-112 for Pacquiao with the third scoring it 114-113 for Thurman.

A jubilant Pacquiao punched the air as the arena erupted after the victory was confirmed. "It was fun," Pacquiao said afterward. "My opponent is a good fighter and boxer. He was strong."

Thurman had riled Pacquiao in the build-up to the fight by vowing to "crucify" his deeply religious opponent, and later promising to send the Filipino icon into retirement.

Pacquiao, who improved to 62-7-2 with 39 knockouts, was gracious in victory.

"I'm not that kind of boxer who talks a lot; we were just promoting the fight," he said. "He's a good boxer and he's strong. I was just blessed tonight."

Pacquiao, who earned an estimated $20 million from Saturday's fight, is now a major player in the competitive welterweight division once again after capturing Thurman's WBA welterweight "super" champion belt.

The eight-division world champion said he will now return to the Philippines to resume his work as a senator before deciding on his next move inside the ring.

"I think I will fight next year," he said. "I will go back to the Philippines and work and then make a decision."

Thurman meanwhile had few complaints in defeat, embracing Pacquiao after the final bell in recognition of an epic contest.

"I knew it was too close," Thurman said. "He got the knockdown so he had momentum in round one.

"This was a beautiful night of boxing. I wish I had a little bit more output to go toe to toe. I felt like he was getting a little bit tired, but he did have experience in the ring. I would love the rematch."

Earlier, a pumped-up Pacquiao had danced into the ring to the strains of Rocky movie anthem Eye of the Tiger to bring the crowd to its feet.

Deafening chants of "Manny, Manny" rolled around the packed arena as Pacquiao immediately set about building an advantage.

Fans in the Philippines on Sunday roared their approval and rose to their feet imitating the punches of Pacquiao, as they declared that their idol was still a boxing force at the age of 40 with his stunning victory over Thurman.

Filipinos from street vendors to lawmakers went wild, pumping their fists in the air during the first round of the welterweight fight as Pacquiao floored the WBA champion 10 years his junior, and went on to win by split decision. 

Despite Thurman's threat to send Pacquiao into retirement, fans of Pacquiao were thrilled to see him eat his words as they packed into gyms, military camps and movie theaters all over the country to watch the fight.