He then stepped up in class, for the first time, when he boxed future world title challenger Josue Marquez in 1971, beating him in a twelve-round decision to claim the Puerto Rican national Lightweight championship.. His next fight was a fourth-round knockout victory over Victor Ortíz.
That changed quickly in his last fight of 1972 against the undefeated new world's Lightweight champion Roberto Durán at the Madison Square Garden arena.
[1][2] In 1973, he was rewarded for his efforts, receiving a chance to challenge Ray Lampkin for the North American Boxing Federation lightweight belt.
In 1975, he went up in weight briefly, and after beating Jesse Lara by a knockout in three, he returned to Panama City to challenge Colombia's Antonio Cervantes for the world's Jr. Welterweight title, losing in a fifteen-round decision.
De Jesús rebounded with three wins before the end of that year, including one over former world title challenger Edwin Viruet.
After beating José Vallejo by a knockout in round seven in San Juan to start 1980, he traveled to Bloomington, Minnesota, to challenge Saoul Mamby for Mamby's WBC world Jr. Welterweight title, in the major supporting event of the Larry Holmes-Scott Le Doux world heavyweight championship bout's undercard.
[3] After it became public knowledge that de Jesús had acquired HIV and had become a sufferer of AIDS, governor Rafael Hernández Colón commuted his sentence.
After returning to spend his last days with his family, de Jesús was visited by many celebrities, including hall of fame baseball player Orlando Cepeda, Salsa music superstar Cheo Feliciano and his old nemesis Roberto Durán.
This event was witnessed by José Torres who said he was amazed to see Durán's compassionate gesture as he lifted de Jesús out of his bed and hugged him at a time when so little was known and so much feared about AIDS.