Christian Medina backed up his WBO super-bantamweight triumph last year with a first defence on home soil as he triumphed against Adrien Curiel.
The Mexican thrilled a Guadalajara crowd as he coasted to a unanimous decision at the city's Domo Alcalde across a dozen rounds to retain his belt.
Medina, who stunned Yoshiki Takei in Nagoya back in September to wrestle the strap away from the Japanese talent, had been tipped for success here.
Curiel, the former IBF light-flyweight champion, had been hopeful however that he could end his countryman's reign prematurely and claim two-weight status.
Ultimately however, Medina controlled the bulk of their encounter, unlocking straight head-body switch combinations to soften his rival up and pin him back.
A crunching right in the eighth round offered a potential opening to finish him off, though Curiel rallied to reach the final bell in his first defeat since 2024.
Medina will now turn to a further defence later this year, or possibly pursue unification routes, with fellow Mexican Jose salas holding the IBF strap himself.
A return to Japan, where has earned the respect of the division, cannot be ruled out either, with Seiya Tsutsumi and Takuma Inoue the current WBA and WBC holders.
Subscribe to DAZN's new Ultimate Tier to get a minimum of 12 PPV events included per year, including Barrois vs Garcia, on top of another 185 fight nights. Plus Serie A football, watch on multiple devices, and many more extra benefits.
Sign up for £22.99 in the UK / $44.99 in the U.S. More details here .