Mayweather could stop Ortiz late, but he wouldn't. I'd say he'd win around 8 rounds to four while giving his face a good cut and/or some decent bruising. Ortiz would catch him a few times early, then Floyd would figure him out and out-do him in the straight-line game with measured counters, since Ortiz doesn't give too many angles, and when Ortiz's athletic and boxing abilities do allow him to get close, Mayweather would outwork him more efficiently on the inside before restarting on the outside and picking him apart. Good amount of activity, fun fight, and probably one of the best opponents for Floyd to ever showcase his talents against: young, fast, strong, hard-hitting, hungry, aggressive, and not unskilled or stupid.
Floyd beats the brakes off even this new axe murderer welterweight version Ortiz. I'm sure Ortiz may land a few decent shots here and there, but Floyd's jab will set up sooooo many other shots, that I figure by the late rounds Floyd will be landing on Ortiz much like he did Hatton by the tenth. Mayweather by Wide UD, possibly late stoppage.
