In his best moments, who would have won?

Roberto Duran vs Lou Ambers, in lightweight.

Roberto Duran [103 (70) -16] boxing from 1968 to 2001. He won world titles in four weight divisions, from lightweight to middleweight. Among his best victories are names such as Ken Buchanan, Esteban De Jesus and Sugar Ray Leonard.

Lou Ambers [89 (28) -8-7] boxing from 1932 to 1941. He twice won the lightweight championship and successfully defended it twice. Among his notable victories are names such as the Cocoa Kid, Tony Calzoneri, and Henry Armstrong.

Opinion: In my opinion, Lou Ambers was very good, people don't usually give him credit. But Duran could box him. In a mid-distance fight I see Duran winning for UD. In a close-range fight it would have been more difficult, as Ambers was very good at the tie, but Duran was also very good, and most likely the fight would have turned this way; I see an SD for Durán.