1983-09-21 Carlos De Leon w rsc 4 (12) Yaqui Lopez, Municipal Stadium, San Jose, California, USA - WBC
1983-09-21 Carlos De Leon w rsc 4 (12) Yaqui Lopez, Municipal Stadium, San Jose, California, USA - WBC. Referee: Henry Elesperu. Making a fast start De Leon (188¾) had his 42-year-old challenger on the deck inside the opening 40 seconds, but then allowed him to recover. After outboxing Lopez in the second De Leon was forced to defend in the third as the Mexican moved his attack to the body, a pattern that continued into the fourth. With Lopez back in the fight it all changed when a long left from De Leon opened up a bad cut over his right eye and led to the referee calling it off at 2.51 of the fourth.
Back in April the recently formed USBA/I had stated that they would recognise S. T. Gordon as champion, but following his defeat at the hands of De Leon the organisation agreed to recognise De Leon. However, in late October, the USBA/I, reconstituted as the International Boxing Federation (IBF), announced that they would now be recognising Marvin Camel (who held the USBA title) as their champion as it had not been possible to induce De Leon to fight under their banner. They then nominated Roddy MacDonald as Camel's first challenger.