A weak con man panics when he learns he's going to prison for fraud. He hires a mysterious martial arts guru who helps transform him into a martial arts expert who can fight off inmates who want to hurt or love him.

Corrales never won another boxing match. A rematch between him and Castillo occurred on October 8, 2005. On the day before the fight, Castillo weighed-in 1½ lb over the 135 lb (61 kg) lightweight limit. Since Castillo did not make the weight, the fight became a non-title bout. The two fighters continued with the same fighting style that they had used in the first fight, trading inside punches throughout the first three rounds. Early in the fourth round, Castillo knocked down Corrales with a left hook to his chin. Corrales wobbled to his feet at the referee's count of ten, causing the fight to end. A third fight between the two was scheduled, but never took place, due to Castillo again coming in overweight and Corrales not willing to have to try to overcome a weight disadvantage again.

Diego Corrales vs. José Luis Castillo was a boxing match in Las Vegas, Nevada, USA, on May 7, 2005. Corrales won the fight in the tenth round after himself being knocked down twice in the round.

In one of the more definitive and memorable fights of his career Mayweather fought the hard-hitting, former IBF super-featherweight champion Diego Corrales (33–0, with 27 KOs). Coming into the bout Mayweather and Corrales were undefeated, and neither fighter had touched the canvas. Mayweather was The Ring's #2-ranked super featherweight in the world (and #7 pound-for-pound), while Corrales was the #1-ranked super featherweight in the world and #5 pound-for-pound.