Tinieblas began as a body builder and stunt man who was spotted by luchadores Black Shadow and Dory Dixon. Impressed by Leal's physique they convinced him to begin a career as a "luchador". In 1968, "Lucha Libre" magazine editor Valente Pérez, came up with the idea of a character that would act as a rival for luchador Mil Mascaras. He created a character with a faceless hood and named him "Tinieblas" (Darkness). Perez selected the former body builder turned luchador to wrestle as that character. Tinieblas debuted as a face on August 20, 1971. He would became a large draw in Mexico and toured internationally. Tinieblas was also one of the first luchadores to tour Japan in 1974.