Eight division world champion Manny Pacquiao clinched his 60th victory with a seventh round knockout Sunday of Argentinean Lucas Matthysse, in what was the Filipino star's first stoppage in nine years.

Pacquiao said he worked hard but was surprised by the swift win in capturing the World Boxing Association "regular" welterweight title.

Pacquiao rebounded from his disappointing loss last year to 2012 Australian Olympian Jeff Horn in July 2017 in Australia, and his victory could extend a boxing career that had taken a backseat to his political life as a Filipino senator.

Matthysse, who capture the title in January, offered up no excuses in what was his third fight at the welterweight limit of 147.

“This is part of boxing. You win some, you lose some,” Matthysse said. He hailed Pacquiao as a “great legend” and said he will take a break after his loss.

According to Pacquiao, he was very cautious with Matthysse's well-known power in both hands. The slugger from Argentina is trained by Joel Diaz, who also trained Pacquiao's former nemesis Timothy Bradley - who the Filipino star defeated with a 2-1 margin in their trilogy.

"Matthysse has power also. It's [He's] an opponent you can't underestimate especially when he threw his wild punches. I cannot underestimate him... I'm not in hurry, just patient and take time," Pacquiao said.

Pacquiao knew right away, when he started landing punches and Matthysse's reactions, that it an early night was very likely.

"From the first round... I know he couldn’t handle my punches, my power," Pacquiao revealed.

Philippine President Rodrigo Duterte and Malaysian Prime Minister Mahathir Mohamad also attended the fight, the biggest boxing match in the country since the 1975 heavyweight clash between Muhammad Ali and Australian Joe Bugner.

“I would like to congratulate Senator Manny Pacquiao for giving us pride and bringing the Filipino nation together once more,” Duterte said.