The 30-second version
- ✓Sergio Mendoza def. Ricardo Sandoval, TKO, round 5 (1:46), for the WBC and WBA flyweight titles. Mendoza is now 28-1 (24 KOs); Sandoval is 27-3 (18 KOs).
- ✓Mendoza knocked Sandoval down three times, twice in round two, and the fight was stopped after the third knockdown.
- ✓He replaced Oscar Collazo, who withdrew with a rib injury; reports put his notice at anywhere from about a week to about three weeks.
- ✓It was Sandoval's first knockout loss and ended a seven-fight winning streak.
- ✓Correction: our October 5 preview listed Collazo vs. Sandoval as the co-feature. Collazo had withdrawn in September, and we have corrected that article.
● The short answer
Sergio 'Yoreme' Mendoza stopped Ricardo Sandoval at 1:46 of round five at the Wintrust Arena in Chicago on October 10, 2026, to win the WBC and WBA flyweight titles. Mendoza, now 28-1 with 24 knockouts, knocked Sandoval down three times, twice in round two, before the referee stopped the fight. He had stepped in on short notice for Oscar Collazo, who withdrew with a rib injury. Sandoval fell to 27-3 and suffered the first knockout loss of his career, ending a seven-fight winning streak. Mexican outlets report Mendoza is the first man born in Hermosillo, Sonora, to win a world title.
Nobody had Sergio Mendoza on the poster until a few weeks ago. On Saturday night in Chicago he left with two world titles.
The fight
Mendoza (now 28-1, 24 KOs) was the underdog against Ricardo Sandoval (27-2 going in). He dropped the champion twice in round two and a third time in round five, and the referee stopped the fight at 1:46. It was Sandoval's first knockout loss and the end of a seven-fight winning streak, and it was one of the bigger upsets in the flyweight division this year.
How he got the shot
Oscar Collazo, the unbeaten strawweight champion who had been due to move up to challenge Sandoval, withdrew in September with a rib injury, and Mendoza took the fight. Reports on how much notice he had range from about a week to about three weeks, so we describe it only as short notice.
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Where he comes from
Mexican outlets report that Mendoza, nicknamed Yoreme, is the first man born in Hermosillo, Sonora, to win a world title, and that he dedicated the win to a brother who died two months earlier. The sanctioning bodies' ratification and mandatory-defense decisions are still pending, according to Titan Sports. Spanish-language coverage: Mendoza noquea a Sandoval (in Spanish).
A correction
Our October 5 Schofield-Bahdi preview listed Collazo vs. Sandoval as the co-feature. Collazo had already withdrawn in September, a fact we missed. The article has been corrected, and we apologize for the error.
The lesson
A short-notice fight is a stress test of your baseline. Mendoza's win does not prove that camps are optional; it shows what a fighter who stays in shape year-round is able to do when the phone rings. If you compete, hold a base level of conditioning and technique that does not depend on a fight date.
Camps build champions. Baselines get them the call.
FAQ
Who won Mendoza vs. Sandoval?+
Sergio Mendoza stopped Ricardo Sandoval at 1:46 of round five on October 10, 2026, in Chicago, winning the WBC and WBA flyweight titles after three knockdowns.
Why did Sergio Mendoza fight Sandoval instead of Oscar Collazo?+
Collazo withdrew with a rib injury, and Mendoza took the fight on short notice.
Has Mendoza's title win been ratified?+
The Mexican outlet Titan Sports reports that the sanctioning bodies' ratification and any mandatory-defense decisions are still pending.
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