Sergio Mendoza Cordova wrecked Ricardo Sandoval’s plans with a fifth-round stoppage, taking the unified WBA and WBC flyweight titles in a fight the defending champion was expected to win Saturday night in Chicago.
Mendoza (28-1, 24 KOs) dropped Sandoval (27-3, 18 KOs) three times at Wintrust Arena, recovering from a second-round knockdown of his own to deliver the biggest victory of his career. The referee intervened in the fifth as Sandoval could no longer cope with the challenger’s attack.
Sandoval had entered his first defense looking to build on the split-decision victory over Kenshiro Teraji that earned him both belts in Japan in July 2025. Instead, his return after more than a year of inactivity ended with those titles heading to Mendoza.
This was supposed to be the night Sandoval got moving again. A successful defense would have allowed him to pursue bigger fights from the position of a unified champion. Now, he faces the task of rebuilding after a damaging defeat, with those opportunities belonging to somebody else.
Sandoval briefly appeared to have the fight moving his way when a right hook put Mendoza down in round two. That success did not discourage the Mexican southpaw, who recovered and used his pressure and punching power to turn the contest.
Mendoza’s three knockdowns made this more than a champion getting caught once. Sandoval could not regain control as the challenger kept hurting him, and the fifth-round intervention ended his hopes of rescuing the defense.
The result was especially unexpected given Mendoza’s recent form. He entered after a second-round knockout loss to Thanongsak Simsri in April, making his U.S. debut as a late replacement and heavy underdog.
Sandoval’s long absence invites questions about his sharpness, but Mendoza supplied the decisive punches. An opponent expected to help launch the champion’s next run instead took both belts and forced Sandoval to start over.
Sandoval walked into Chicago treating Mendoza like a stay-busy fight to dust off fifteen months of rust, and he paid the ultimate price for it. When a unified titleholder sits out for well over a year, thinks he can just show up against a heavy puncher, and gets dragged into a firefight, this is exactly what happens.
