Juan Díaz has four losses against three opponents on his boxing record. For a list of Díaz's best fights, refer to "Best fights of Juan Díaz".
On July 31, 2010 Juan Díaz fought Juan Manuel Márquez in a lightweight world-title fight for Márquez' WBA (Super), WBO and The Ring titles. Díaz was 26 years old and with a record of 35-4 (17), and Márquez was 36 years old and with a record of 50-5-1 (37). Díaz lost the fight via 12-round unanimous decision.
On December 12, 2009 Juan Díaz faced off against Paulie Malignaggi in a super-lightweight bout at age 26. He was coming in with a record of 35-3 (17), and Malignaggi was 29 years old and with a record of 26-3 (5). Díaz lost the fight via 12-round unanimous decision.
On February 28, 2009 Juan Díaz fought Juan Manuel Márquez in a lightweight world-title fight for the The Ring, WBA (Super) and WBO titles. Díaz was 25 years old and with a record of 34-2 (17), and Márquez was 35 years old and with a record of 49-4-1 (36). Díaz lost the fight via 9th-round TKO.
On March 8, 2008 Juan Díaz met Nate Campbell in a lightweight (WBA (Super), IBF, WBO) world-title defense fight. Díaz was 24 years old and with a record of 33-1 (17), and Campbell was 36 years old and with a record of 31-5-1 (25). Díaz lost the fight via 12-round split decision and lost the titles.
