Miguel Cotto again looked superb as he beat the dangerous Victoriano Sosa in for one-sided rounds in Las Vegas.
Cotto produced another controlled but aggressive display and had Sosa down three times in all before the fight was waved off in the fourth.
The Puerto Rican defended his WBC International light-welterweight title for the fourth time and moved his record to 19-0 (16) as a result.
Cotto is regarded by many as the brighest star of a 10st division rich in talent, and may yet face Manchester's Ricky Hatton somewhere down the line.