Ricardo Sandoval’s first defense of his unified flyweight titles ended in disaster as Sergio Mendoza Cordova dropped him three times and forced a fifth-round stoppage Saturday night at Wintrust Arena in Chicago.
Mendoza (28-1, 24 KOs) took the WBA and WBC belts from Sandoval (27-3, 18 KOs), turning a late replacement appearance into a career-changing victory. Sandoval was supposed to get through this fight and move toward bigger opportunities. Instead, he left with his title plans torn apart.
The warning about Mendoza was there in his record: 23 stoppages from 27 victories entering the fight. His second-round knockout loss to Thanongsak Simsri in April made him look vulnerable, but it did not erase the danger in his punching.
Sandoval had his own success, knocking Mendoza down with a right hook in the second round. That should have given the champion something to build on. Mendoza recovered, however, and Sandoval could not prevent the southpaw from taking over with pressure and heavy shots.
Three knockdowns told the story. This was no narrow defeat that Sandoval could dispute afterward, and the referee’s intervention in the fifth prevented him from taking further punishment.
The loss also changes how Sandoval’s lengthy absence looks. After beating Kenshiro Teraji by split decision in Japan in July 2025, he spent more than a year outside the ring before defending his belts. Whatever the reasons for that delay, his return offered none of the momentum he needed.
Winning two titles had put Sandoval in position to pursue bigger fights. Losing both in his first defense leaves him needing to rebuild, without the championship status that helped make those fights possible.
Mendoza deserves the credit for refusing to let his own knockdown decide the contest. He arrived as an underdog making his U.S. debut, absorbed an early setback and kept attacking. Sandoval had the plans, but Mendoza had the punches to wreck them.