Fidel “The Atrisco Kid” Maldonado Jr. of Albuquerque stopped late substitute John Nater of Puerto Rico after four rounds of their junior welterweight main event Monday night at Cowboys Dance Hall in San Antonio. The Golden Boy Promotions/Leija*Battah Promotions card was televised on Fox Sports 1.

The hard-hitting Maldonado (18-2, 15 KOs), just 22, decked Nater in the third and fourth rounds on the way to his fourth consecutive knockout. Nater did not answer the bell for the fifth of the scheduled 10-round bout.

Nater, 23, is 13-5 (10 KOs). He was a replacement for Steve Forbes, who could not pass a pre-fight medical examination.