Tommy Hearns would be a nightmare for Mayweather, imo. Just too long and powerful, naturally MUCH bigger... PLus I seriously doubt Mayweather could hurt Hearns even if he landed his best shots repeatedly.. Hearns chin is underrated. It wasn't total crap like some ppl think, he never got hurt by anything but a great punch, Hagler landed alot on him before he got the KO, as did SRL obviously.. and so I don't see any way Floyd could even hurt him. Hearns would have a field day, he could just jab past mayweathers guard, even just to the chest... Mayweather has brilliant defense but it wouldn't mean a whole lot against Hearns, who could sit back and attack PBF against the ropes while staying out of range himself.. I honestly think Tommy could break through Mayweathers defense just by using the jab consistently, and by the later rounds he would take total control.