The most debated fight in Floyd Mayweather Jr.'s undefeated career is unquestionably his first bout with Jose Luis Castillo on April 20, 2002. Mayweather was 27-0 and moving up to 135 pounds for the first time, where Castillo (45-4-1, 41 KO at the time) held the WBC's title. Their rematch a few months later would decide the Ring Magazine lightweight championship, crowning Mayweather as the division's first Ring champion since Pernell Whitaker moved up to 140 pounds in 1992.