Pintor, nicknamed El Indio De Cuajimalpa (The Indian From Cuajimalpa) started his professional boxing career in 1974, when he beat Manuel Vazquez by a knockout in two rounds. He was fighting in ten rounders as soon as his second bout, when he beat Francisco Nunez by a decision in 10. By his fifth bout, he suffered his first loss, beaten on a disqualification against Magarito Lozano. He then won his next eight bouts, seven by knockout, including wins over Juan Diaz, Rocky Mijares and Willie Jespen.
Pintor first boxed the future world Bantamweight champion Alberto Davila on February 25 of 1976, and he lost to Davila by decision in 10. Then, he won 22 more fights in a row. Included among the fighters he beat during that span were Nacho Beltran, Evaristo Perez, Eduardo Limon (who is the brother of two time world champion Rafael Bazooka Limon), Gerald Hayes, a man who later beat Juan Laporte, and Antonio Becerra, a Mexican regional Bantamweight champion who beat Salvador Sanchez.
Then, he travelled to Puerto Rico, and lost a 10 round decision to Dominican Leo Cruz, a future world Jr. Bantamweight champion himself. Back in Mexico for a comeback fight, Pintor lost for the second time in a row, this time to future Wilfredo Gomez rival Jose Luis Soto, by a decision in 10. He then embarked on another winning streak, winning five fights in a row by knockout. After beating Nivio Nolasco in six, he was the WBC's number one Bantamweight challenger. After beating Rodrigo Gonzalez by a knockout in three, Pintor was signed for his first world championship try.
This championship try brought a conflict of interest because the world champion, Carlos Zarate, was his gymmate. In any case, Pintor won by a split 15 round decision, after going to the canvas in round four. Pintor became world champion, but his relationship with Zarate, already strained, took another hit, and he and Zarate have publicly debated the result of that fight for the last two decades after their confrontation.
Pintor was a busy champion, and he began by doing three non title bouts, beating Ausencio Melendez by a knockout in the first, avenging his loss to Lopez, with a ten round decision win, and losing to Manuel Vazquez by a knockout in six, in a rematch fight. Then, his title defenses began, and he retained the title with a knockout in twelve over Alberto Sandoval in Los Angeles, and a draw in fifteen with Eljiro Murata in Nagoya.
His next bout brought a touch of tragedy to his career. He defended against Johnny Owens of Wales in Los Angeles. Many of the fans present and the book The Ring: Boxing in The 20th Century, have agreed that the fight should have been stopped during round 10. But the fight lasted until round twelve, when Pintor was awarded a knockout win. Owens subsequently collapsed, and he died a few days later.
Pintor re-took his career and was able to avenge his loss to Davila in his next fight, retaining the title with a decision in fifteen, and then he retained the belt against Jose Uziga, again by decision, and Jovito Rengifo, by a knockout in eight. He knocked out Hurricane Teru in the 15th and final round to close 1981, and began 1982, retaining the belt against Seung-Hoon Lee by a knockout in eleven. After the defense with Lee, Pintor was already looking at the Jr. Featherweight division where Gomez was world champion. He went up in weight and beat former Bantamweight world champion Jorge Lujan, already a Jr. Featherweight also, and then, on December 3 of that year, he and Gomez met as part of the Carnival of Champions in New Orleans. In what was the only HBO Boxing appearance ever for both Gomez and Pintor, they battled in what The Ring: Boxing in The 20th Century called one of the most brutal fights of 1982, and Ring Magazine called the Fight of The Decade at the Jr. Featherweight division. But Gomez retained his title by a knockout in the 14th, and Pintor was left to make a decision: He had to decide whether he wanted to fight at a heavier weight, or go back to the Bantamweights and keep as world champion there.
Pintor had a life threatening accident in 1983, and he broke his chin, requiring hospitalization. Because of that, he had to vacate the bantamweight title anyways, so he decided to campaign as a Jr. Featherweight. He had to take one year and a half off, and then he came back on February 16 of 1984, beating Ruben Solorio by a decision in 10. Two more wins, including one over former world title challenger Cleo Garcia by a knockout in the first, and Pintor was faced with Adrian Arreola, losing by a knockout in seven.
However, after beating Eugenio Morgan by a knockout in two, the WBC gave Pintor another try at the world's Jr. Featherweight title, pitting him and world champion Juan Kid Meza inside a ring at Aguascalientes. Pintor floored the defending champion three times, and went on to become a two division world champion with a 12 round unanimous decision win.
For his first defense of his second title, Pintor travelled to Bangkok, Thailand, where he met Samart Payakaroon, losing by a knockout in five in what would turn out to be his last world title fight.
He announced his retirement then, but, like many other boxers, he came back, and from 1994 to 1995, he won 2 fights and lost five, finally convincing himself it was time to retire.
Pintor managed his money well, and he recently opened a boxing school in Mexico City. He stirred up some controversy recently by describing former gymmate and rival Zarate as a person who acted unfriendly and as a divo during the time Zarate was champion.
Pintor retired with 56 wins, 14 losses and 2 draws, with 42 wins by knockout.