During his career, which lasted from 1982 to 1993, Nazario won the WBA world lightweight title.

Nazario was able to reverse the result of the first fight by beating Rosario in the eighth round to become champion.

In his first defense Nazario challenged Pernell Whitaker for the undisputed title.

Whitaker won the fight in the first round and Nazario never fought for a world title again.

Nazario fought for a final time on July 10, 1993, beating Angel Cordova by unanimous decision.