It was all Kazuto Ioka from bell to bell as he out-boxed Thai veteran Noknoi Sitthiprasert to retain the WBA flyweight title on Sunday at EDION Arena in his hometown of Osaka, Japan.

Two judges scored the fight 117-110 and the third had it 116-111 for Ioka, who makes the second defense of the belt that was elevated to full championship status after Juan Francisco Estrada vacated his unified title.

Ioka (22-1, 13 knockouts) used his superior jab to keep the durable, if predictable Noknoi at bay, forcing him back with creative combinations, like an uppercut to the body followed by double overhand rights and a left hook in the fifth round, or a double left uppercut to the head followed by a left hook to the body in the sixth.

The constant barrage of blows which the hometown fighter rained down on his Thai visitor began to rearrange his face, beginning with a cut on the bridge of his nose in round six, and a stagger near the end of the eighth after Noknoi (62-5, 38 KOs) jumped in with a left jab, had it parried, and then Ioka filled the gap with a right hand to the chin that Noknoi never saw coming.

As futile as his offense was, Noknoi proved durable, remaining on his feet in an eleventh which could be a case study for a 10-8 round. At the 1:10 mark of that round, Ioka rolls off a pair of punches, then finishes Noknoi’s combination with a right hand and a left hook to the chin that made his head pivot and jerk violently. Noknoi remained standing, and as a show of pride in his first title fight after 66 previous fights, he landed a short uppercut in close.

The loss was Noknoi’s first since 2005, when he lost four of his first five fights before winning his next 61 fights against mostly average Southeast Asian opponents in Thailand.

Ioka is the number one rated flyweight in The Ring ratings.