Rojas claimed the World Boxing Assn. belt on March 28, 1968, beating Colombian Enrique Higgins by decision at the historic Olympic Auditorium in Los Angeles.
"Rojas always drew a good crowd and was a popular main-eventer because people knew if you saw him fight, you'd always get your money's worth," said former fight publicist Don Fraser, whose California Boxing Hall of Fame counts Rojas as an inductee.
With a career record of 38-7-2 with 24 knockouts, Rojas packed them into the Olympic against the likes of Cuba's Sugar Ramos and Mando Ramos in his final fight, a technical knockout loss on Dec. 10, 1970.
He first had a featherweight title shot at World Boxing Council champ Vicente Saldivar in May 1965 at the Coliseum, but was easily being outpointed when the fight was stopped in the 15th round.
Rojas was born Nov. 5, 1941, and grew up in Watts and East Los Angeles. Two of his brothers were sent to San Quentin State Prison. Rojas led a group called "Little Roy's Gang," according to a 1968 Sports Illustrated article, and was sent to the California Youth Authority following a violent clash in which a fellow gang member was shot dead next to him, "a bullet between his eyes," according to the story.
"All I ever was was tough," Rojas said. "I thought I'd put it to work."
As he told The Times in 1968: "If it were not for boxing, I'd probably either be in San Quentin or would already have made the trip to the gas chamber."
After his boxing career ended, Rojas worked as a longshoreman, Fraser said.
Rojas is survived by his daughters Rebecca and Guadalupe and grandchildren.