Juan Manuel Marquez vs. Juan Diaz I Full Fight

On February 28, 2009, Márquez defeated former WBA, WBO & IBF Lightweight Champion Juan Díaz by knockout. Díaz controlled the fight early in the bout as the two boxers exchanged punches.

Díaz opened a cut above Márquez's right eye in the fifth round and looked to control the bout, but Márquez responded by opening a gash above Díaz's right eye and stunning him with a left hook before the end of the eighth round. Márquez landed two hard rights to Díaz's face in a three-punch combination that knocked Díaz down with 35 seconds remaining in the ninth round.

Díaz rose, but seconds later, Márquez followed with a right uppercut to the chin that knocked Díaz down for a second time. Referee Rafael Ramos waved an end to the fight after two minutes and 40 seconds of the ninth round. With the victory, Márquez defended his The Ring Lightweight title and claimed the vacant WBO and vacant WBA (Super) Lightweight titles.