De La Hoya took promoter Bob Arum to court in the fall of 2000, trying to break his contract with the promoter.
The courts ruled in favor of De La Hoya in February 2001.
After seven defenses of his lineal and WBC welterweight titles, De La Hoya fought rival and IBF Champion Félix Trinidad (35–0) on September 18, 1999, in one of the biggest pay-per-view events in history, setting a record for a non-heavyweight fight.
Oscar dominated the vast majority of the first nine rounds, staying just outside Trinidad's range while generating much success with his stiff jab and blitzing combinations.
The fight was a disputed decision, with one judge scoring the fight 115–113 for De La Hoya, and the other two scoring it 116–112 and 115–113 for Mosley.In his first title defense, he defeated John-John Molina (36–3), who had recently vacated his IBF Super Featherweight title, by unanimous decision.On May 6, 1995, De La Hoya defeated IBF lightweight champion Rafael Ruelas (43–1–0) in a unification bout."Bob Arum's people hope I lose because they can't see a Mexican above them, and also that he defeated one of the biggest Jews to come out of Harvard." De La Hoya did not fight for the 15 months and in this time the rivalry between him and WBA champion "Ferocious" Fernando Vargas (22–1) grew. The fight was scheduled for early 2002, but De La Hoya had to withdraw because of a hand injury.They knew each other as amateurs and it is said the rivalry began when Vargas was angered by De La Hoya laughing at him after he fell into a snowbank. The unification bout, labeled "Bad Blood," finally took place on September 14, 2002, at the Mandalay Bay on the Las Vegas Strip.