Sept. 15, 2012 // 9 p.m. ET; 6 p.m. PT (HBO PPV)
Thomas & Mack Center, Las Vegas
Martinez's body is a testimony to his flawless conditioning. He's as sharp and cut as an underwear model 15 years his junior -- and in this case, looks are anything but deceiving. Martinez routinely outworks younger contenders for 12 rounds while seemingly failing to break a sweat, and he often brings on extra pressure down the stretch, when most fighters would be protecting their lead. It's hard to tell whether Chavez's blocky physique is really hiding a rock-hard six-pack, but he looks flabby enough at his weigh-ins (and plodding enough in the ring) to lead us to believe that he could stand to put in a lot more work in this department.
Written by Diego Morilla