Antonio José Díaz Fernández was born in Caracas, Venezuela, on June 12, 1980. At the age of 6, he began his karate training under the influence of his father, and in 1993, he obtained his first gold medal as a member of the national team in the V Youth Pan American Karate Championship, held in Puerto Rico, where he participated in the kumite competition. However, years later, at the age of 19, as he began to compete in adult tournaments, he specialized in kata.

Díaz also has a degree in Social Communication from the Andrés Bello Catholic University, based in Caracas. Along with his competitive career, he became part of the Athletes Commission and the Kata Rules Commission of the World Karate Federation. This was a great motivation for him, as it enriched his career by making him the voice of the athletes at an institutional level.

He had planned retiring from competitions in 2016, but that very year karate was included in the program of the Tokyo 2020 Olympic Games. With his classification and participation in the event he closed a cycle. He now continues his coaching career, always with the feet on the tatami.