Floyd Mayweather retained his WBC welterweight title and his unbeaten record with a convincing points victory over Robert Guerrero.
The American showed little sign of ring rust in his first bout for over a year as he weathered an early storm and dominated the laters rounds to earn a unanimous decision 117-111 on all three cards.
Guerrero attempted to assert himself in the second round, pinning Mayweather on to the ropes with a series of well-timed blows with his left.
But Mayweather's class was evident in the next round as he landed some damaging blows himself, and he continued to set the tempo while keeping his compatriot's brief attacks at bay.
Damage around Guerrero's eye opened up into a cut by the eighth round, in which his knees briefly buckled after a series of big rights, but he gamely tried to force his way back into the reckoning with some energetic combinations.
But the effort took its toll and Mayweather looked comfortable over the last third of the fight, picking off Guerrero almost at will as his superior speed and movement told.
Mayweather was barely marked as he finished the bout with a 60% success rate with his power punches while handing Guerrero only his second defeat of his 33-fight professional career.
"We did it again," said Mayweather after his 44th victory in as many professional contests. "I take my hat off to Robert Guerrero. He's a true warrior.
"I feel bad I didn't get the knockout that the fans wanted. I was still trying to go for the knockout but it didn't happen."
Mayweather also paid tribute to his father and trainer, Floyd Mayweather Snr, adding: "I needed my father tonight. My defense was on point and he told me to stick with my defence and that the less you get hit the longer you last."
Guerrero said: "I landed some good shots on him, but he's a great fighter. He's slick and quick."