I don't know if it would be more lopsided, Pac presents an entirely different challege, but I still think Mayweather would win decisively. I think if he'd gone all out he could've stopped Marquez tonight and I think he'd be able to do the same thing to Pacquiao. I do think a Pacquiao - Mayweather fight would be more competitive though.

IMO, Pac and Williams are the two biggest threats to Mayweather, and not necessarily in that order.