"Sugar" Shane Mosley claimed the interim WBC welterweight title with a convincing unanimous points victory over Luis Collazo in Las Vegas at the weekend.
Collazo lost his IBF version of the title to Ricky Hatton, but was looking to reclaim a belt quickly as he went up against 35-year-old Mosley.
Judges scored the 12-round bout 118-109, 118-109 and 119-108 in favour of Mosley, who also put Collazo on the floor in the 11th round in the only knockdown of the contest.
Mosley has mainly been fighting at light middleweight, but was happy to drop back down a weight to take on New York-born Collazo in Vegas.
Mosley, who had previously held the title from 2000 to 2002, will progress to full champion status when Floyd Mayweather Jr fights Oscar De La Hoya for the light middleweight crown in May.
Collazo could not match Mosley's speed and reflexes despite the older man normally fighting at a heavier weight, and this was evident in the number of punches landed.
Mosley threw 601 punches and landed 200, while Collazo connected with just 87 of his 639 attempts.
Such figures showed why Collazo only won the second round on all three judges' score cards.
Collazo was on the ropes and struggling in the eighth as Mosley unloaded a speedy combination of punches. In the 11th round a right hand to the temple put him down.
The victorious Mosley, who believes he still has plenty left in the tank despite his advancing years, said: "It feels good to be a welterweight again. I felt light on my feet."
Collazo's record now reads 27-3 with 13 knockouts after his latest defeat, which he partly blamed on picking up a hand injury in the third round.
"I hurt my hand in the third round and I wasn't able to fight the way I wanted to," Collazo said.
"I hurt it in training camp. I wish I could have been more effective. That was the best I could do.