Luján was born in Colon, and began his professional boxing career by knocking out one Baby San Blas III in one round on June 16, 1973, at Gimnasio Nuevo Panama (now Roberto Durán Arena).
He ran a record of 4-0 with 2 knockouts and then met future Guty Espadas world title challenger Alex Santana, 0-1 at the time.
Jorge Luján obtained three more wins, including one over 10-2-2 prospect John Cajina, before going against Reyes Arnal, who was 5-1-2 and who'd later on lose a close, 15 round split decision to Miguel Canto in a challenge for the Hall of Famer's WBC world Flyweight title.
On November 19, 1977, in what also constituted Luján's debut in the United States as a professional boxer at the Los Angeles Sports Arena in Los Angeles, California, Luján built a six-point lead in one judge's scorecard and four point leads in the other two scorecards before becoming world champion by knocking Zamora out in round ten.
Luján was a busy champion, defending his title with success five times in the next three years, including an eleventh-round knockout of Mexico's Roberto Rubaldino at the Freeman Coliseum in San Antonio, Texas after Luján had been dropped in round one on Luján's birthday of March 18, 1978; a fifteen-round decision win over future world champion Alberto Davila at the Superdome, New Orleans, Louisiana as part of the second Muhammad Ali-Leon Spinks fight's undercard on September 15, 1978;[1] his Caesar's Palace debut when he beat Cleo Garcia with a technical knockout at 2:29 of round fifteen on April 8, 1979; a rematch win against Roberto Rubaldino, this time stopped in round fifteen at the La Villa Real Convention Center in McAllen, Texas on October 6, 1979, and a ninth-round knockout win over challenger Shuichi Isogami at the Kuramae Kokugikan, Tokyo, Japan on April 2, 1980.
Then, on May 14, 1983, Luján met Mario Miranda, who had just come off an unsuccessful bid for the vacant WBC world Featherweight championship versus Juan Laporte.
Another huge mismatch took place on November 26 of 1983 at the Nuevo Panama Gym when Luján, now fighting at Junior Lightweight, took on one Wilson Peraza, who was making his professional boxing debut versus the former world champion.
Luján faced a more experienced rival on June 30, 1984, when he fought Colombia's former WBA world Super Bantamweight champion, Ricardo Cardona, who was 26-9-1 coming in.
This bout was to determine WBA world Featherweight champion Eusebio Pedroza's next opponent, and Luján won by scoring a tenth-round knockout over the Colombian.
[2] Luján took off ten months after the Pedroza loss, and returned on December 14, 1985, to face local prospect Jose Marmolejo, who was 11-2 in 13 previous bouts.