He started as a professional on February 29, 1964, knocking out Freddie Garcia in round one at Cuernavaca. With that knockout win, a streak of 22 knockout wins in a row had been set off. During that streak, he beat Tony Gallegos, Monito Aguilar and Antonio Leal, among others. It was on March 8, 1967, that Felipe Gonzalez became the first one to go the distance with Olivares, when Olivares defeated him by a decision in 10 at Mexicali. Then, on July 29 of that same year, Olivares had the first spot on his record, German Bastidas holding him to a ten round draw.
He had back to back rematches with Gonzalez and Bastidas, knocking Gonzalez out in round six on November 19, and Bastidas in round four on January 28, 1968. Then came a step up in opponent quality, when he met former world champion Salvatore Burruni in Mexico City. Olivares knocked Burruni out in three rounds. After defeating Manuel Arnal by a disqualification in six, he set off on another knockout win streak, this one reaching 21 in a row. One of the fights in that streak was against Bernabe Fernandez, in Los Angeles. Olivares won his first fight abroad that day, beating Fernandez in round three.
Another of the fights in that streak was against world Bantamweight champion Lionel Rose, who was defending his world title that day, at the Inglewood Forum. According to boxing book The Ring: Boxing in The 20th Century, the forum's director, fearing a riot like the one that happened after Rose had beaten Chucho Castillo there might happen again, went to Olivares' locker room to express his worries, and Olivares guaranteed he wouldn't let that happen again. Olivares became world Bantamweight champion by knocking Rose out in round five on that day, August 22 of 1969.
After beating Alan Rudkin in a title defense and a couple other fighters in non-title bouts, Olivares started his trilogy of bouts with arch-enemy and countryman Castillo. Olivares' knockout streak ended in that fight, but he won the first installment of the Olivares-Castillo rivalry after rising off the canvas to score a 15 round decision. After three more non-title wins, Olivares and Castillo met again, on October 16 of 1970. This time, Olivares suffered a cut in round one, and the fight was stopped in round 14, Castillo the winner and new world Bantamweight champion by a technical knockout.
After one more win, Olivares and Castillo had their rubber match, on April 3 of 1971. Olivares was knocked down once, but he rose to regain the world Featherweight title in the last fight between he and Castillo with another 15 round decision. Then, he had six more knockouts in a row, including one in a non-title bout in Nicaragua, one in Tokyo while defending the crown against Kasuyoshi Kanazawa (in round 11), and one against Jesus Pimentel, also in round 11.
On March 19, 1972, he lost the world's Bantamweight title to another countryman, Rafael Herrera, by a knockout in round eight. After defeating Godfrey Stevens in Monterrey, he and Herrera met again, with Herrera the winner by a 10 round decision.
Next for Olivares was a move up in division, and he started to campaign in the Featherweight division. On June 23 of 1973, he met Bobby Chacon in the first installment of another trilogy of fights. What was contested for the NABF featherweight title, ended in round nine when Olivares knocked Chacon out. In his next fight, he suffered an upset, when unknown Art Hafey knocked him out in five rounds, but then he set off on a string of three more wins in a row, including a decision over Hafey in a rematch, before fighting for the WBA's vacant world Featherweight championship. On July 9, 1974, Olivares became world Featherweight champion by beating Zenzuke Utagawa by a knockout in round seven. After two non-title wins, he met Alexis Arguello on November 23 of that year, losing the world title by a knockout in round 13.
One more win, and Olivares met Chacon in the second installment of their trilogy, this time with Chacon as the WBC's world Featherweight champion. Olivares won the fight by a knockout in round two, to become world champion for the fourth time. This time, however, he also lost the title in his first defense, beaten by Ghana's David Poison Kotey, who became that nation's first world boxing champion ever by winning a 15 round decision against Olivares. A seven round knockout defeat at the hands of future world champion Danny Little Red Lopez followed.
Olivares won three fghts in 1976 without losing one, including victories over world title challengers Fernando Cabanela and Jose Cervantes, both of them from Colombia. In 1977, he and Chacon boxed the final bout of their trilogy, and this time Chacon came out the winner, by a 10 round decision. But in 1978, Olivares found what would be the beginning of his last hurrah, as he knocked out the future 2 time world Lightweight champion Jose Luis Ramirez in two rounds at Ciudad Obregon, and he followed that win with wins over Shig Fukuyama and Isaac Vega.
After drawing in ten rounds with Guillermo Morales on April 22, 1979, he received what would turn out to be his last world title try: On July 21 of that year, he was knocked out in 12 rounds by WBA world Featherweight champion Eusebio Pedroza in Houston, for the WBA Featherweight title.
For the next eight years, he fought sporadically and with mixed success, until he was able to walk away from professional boxing in 1988.
Until Julio Cesar Chavez came into the scene, Olivares was the boxer most fans recognized as Mexico's greatest boxer ever. He became a mainstream star there, and he reportedly had friends in the Mexican entertainment world. In addition, he could be seen fairly often doing cameos in Mexican comedy movies. He is still considered a national hero there.
But, just like with many other celebrities, celebrity was not all pink colored for Olivares: He was rumored to have to fight off an alcohol problem, although no evidence of that actually happening ever surfaced.
He had a record of 88 wins, 13 losses and 3 draws, with 78 wins by knockout. His knockout winning streaks of 22 and 21 in a row qualify as two of the longest knockout winning streaks in the history of boxing. Similarly, his 78 knockout wins make him a member of the exclusive group of boxers to have won 50 or more fights by knockout.
Olivares, like Arguello, is a member of the International Boxing Hall of Fame.