May 4, 2013 // 9 p.m. ET (Showtime PPV)
MGM Grand, Las Vegas
Guerrero modified his diet and preparation for this fight, putting in long hours during training camp to improve in this area. Not that he had been a slouch in the past. Guerrero showed resolve in recent 12-round decisions over big hitters Selcuk Aydin and Andre Berto, both of whom he outpunched by wide margins. But Mayweather, by comparison, is a far more gifted and calculating foe -- one who will pounce on any fatigue-induced mistake. Renowned for his grueling workouts and late-night runs, he has yet to meet an opponent who can outlast him.
Written by Bernardo Pilatti