The 23-year-old hometown fighter brought his record to 11-0 with his seventh career KO over the Mexican, whose record now reads 28-2. It also makes Ioka a two-weight world champion with less than a dozen professional outings to his name.
The bout was Ioka’s first at light-fly having stepped up to 108lb after unifying and then vacating the WBA and WBC strawweight belts earlier in the year.
A very physical fight saw the Japanese boxer knock his opponent down once in the opening round and then twice more in the sixth before proceedings were halted.
The WBA strawweight title given up by Ioka was claimed in a bout on the Osaka undercard by Ryo Miyazaki, who outpointed former champ Pornsawan Porpramook of Thailand via split decision.
Scorecards of 116-111 and 116-112 for Miyazaki brought his unblemished streak to 11-0 (six knockouts) in the biggest win of his fledgling career to date. The third judge had Porpramook 114-113 ahead.
In an earlier fight on the same card, Solomon Haumono moved to 5-0 by ending the five-fight winning streak of Kyotaro Fujimoto with a fifth-round knockout.