Las Vegas, May 3 (IANS): Boxer Floyd Mayweather Jr. beat Manny Pacquiao by a unanimous decision in the "Fight of the Century" to improve his overall fight record to 48-0 here.

Mayweather survived an early assault by the Filipino and then won the later rounds to finish ahead on all three judges' scorecards in a welterweight showdown on Saturday that is expected to be the most lucrative fight of all-time, reports Xinhua.

Mayweather is guaranteed at least $120 million from the title bout that had been dubbed the "Fight of the Century" and he said in the ring that his next fight will be his last.

"My next fight in September will be my last and I will retire 49-0," said the 38-year-old American.

"It is a good fight. I thought I won the fight. He didn't do nothing. He always moved outside," said Pacquiao, who dropped to a overall fight record of 57-5-3.

"I got him many times. I threw the punches and I thought I won the fight."