On September 6, 2025, Eduardo Núñez defeated Christopher Díaz-Vélez by unanimous decision in a 12-round junior lightweight bout for the IBF junior lightweight title at Centro de Usos Múltiples in Los Mochis, Sinaloa, Mexico. Núñez used his pressure, body attacks, and powerful combinations to control the action, dropping Díaz-Vélez twice in the seventh round. Díaz-Vélez showed toughness and fought competitively until the final bell, but Núñez retained his world title with scores of 117–109, 117–109, and 116–110.