Complex sentence: He defeated Fernandez by technical knockout in the 8th round on July 15,1975, to set a world record for taking the shortest time to win the world title; it had been less than a year since he made his debut in 1974.
Split into simpler sentences: He defeated Fernandez by technical knockout in the 8th round on July 15,1975 to set a world record for taking the shortest time to win the world title. It had been less than a year since he made his debut in 1974.