Limon found out he had talent for the sport and was sent to train with former professional boxer and noted trainer Kid Rapidez after three months learning to box while with the Army.
Their first fight took place on 7 December 1975, in Mexicali, Mexico, Limón defeating a heavily favoured Chacon in a ten-round unanimous decision (UD).
Limón challenged WBC super featherweight champion Alexis Argüello in February 1979, suffering an eleventh-round knockout (KO).
Following this he and Chacon met for the second time, an accidental clash of heads resulting in a seven-round technical draw (TD).
Limón knocked out Venezuela's Idelphonso Bethelmy in the fifteenth round at Los Angeles to become the WBC super featherweight champion.
Limón climbed the ropes to get to his feet to finish the fight, yet lost on the judges' cards in a close unanimous decision.