Super Feather - Azumah Nelson

Lightweight- Roberto Duran

Super Lightweight- Kostya Tszyu/Aaron Pryor

Welterweight - Sugar Ray Leonard/Tommy Hearns

All of the above in ther prime would give Mayweather hell.

Mosley was 8-9 years from his prime.

What i saw in Round 2 when Mosley caught Floyd, convinces me Tzsyu would have landed his right hand at some point, his hand speed and accuracy was exceptional.