Uchiyama is widely recognized as the best super featherweight in the world. With that comes responsibility of leading by example. In that regard, the division has been slowed to a crawl in 2014, due to inactivity at the top level. The lone other threat to the crown for most of the year was Mikey Garcia.
In that regard, both fighters have fallen well short of carrying momentum in the division. Garcia has spent most of the year embroiled in a legal battle with promoter Top Rank, while Uchiyama hadn't fought since last New Year's Eve, nursing injuries and choosing to preserve his 35-year old body rather than rush back to the ring.
Ring rust was evident early, or perhaps the defending titlist has slowed down a notch. Either way, Uchiyama had a fight on his hands early on, as Perez showed no fear nor any signs of backing down.
The heart and determination of the visiting Argentine were admirable, but also attributable to his downfall. Uchiyama is no stranger to getting his hands dirty, and - despite the extended break from the ring - was fully prepared to fight in the trenches.
As the fight wore on, the bruising pace took its toll on Perez. The closest he came to disrupting his opponent's rhythm was when he shoved the defending champ to the canvas in round eight.
Uchiyama made the challenger pay in round nine, delivering a vicious beating and coming dangerously close to knocking him out. Perez barely made it out of the round, but had the fight beaten out of him by that point. as his handlers demanded he remain on his stool at the start of round ten.
The timing of the win means Uchiyama will get to celebrate five years as champion in January, having begun his reign with a 12th round stoppage of Juan Carlos Salgado in 2010. Wednesday's win marked the ninth successful defense of his crown, as he improves to 22-0-1 (18KOs).
Perez falls short in his first title bid, as his record dips to 27-3-1 (16KOs). The loss was his first in nearly 12 years, enjoying a 19-fight unbeaten stretch since March '03.
The bout aired live on TyC Sports in Argentina, and is due to air via same-day tape delay on TV Tokyo in Japan.
Also on the show:
Jake Donovan is the Managing Editor of BoxingScene.com, as well as the Records Keeper for the Transnational Boxing Ratings Board and a member of Boxing Writers Association of America. Twitter: @JakeNDaBox