He proved as much versus the 33-year old Yaegashi, who on any given night could look like he's either one of the best action fighters in the world or one punch away from retirement. Sensing that everyone is coming for his crown, Yaegashi decided to box a bit more, fighting in reverse and allowing Tecuapetla to come to him.

It seemed like a matter of time before he would eventually find himself in a war. That moment came in round three, one of several that can be pinned to the boxing bulletin when considering Round of the Year candidates once we near the end of 2016. Both fighters stood toe to toe in the final minute, Yaegashi scoring with sizzling right hands, while Tecuapetla allowed his body shot attack to create openings upstairs. 

The round set the tone for the remainder of the fight, even if it was Yaegashi who tried to always return to calmer pace against his 26-year old challenger. The strategy held up during the middle rounds until Tecuapetla was able to close the gap late in round eight and into the ninth frame. His height and reach advantages weren't put to use in the boxing sense, but rather to draw in the defending champ and not allow him anywhere to go once the bout was fought at a phone booth's distance. 

Not only was it winning rounds for the challenger, but Yaegashi - who cuts and swells from walking outside on a windy day - was forced to contend with compromised vision through his left eye heading into the championship rounds. Round 11 was another for the time capsule as Yaegashi emptied both clips looking to close the show, only to have to fend off a rallying Tecuapetla in the closing seconds of the frame.

Fittingly, it was trumped from an action standpoint by what took place in the final three minutes of the fight. Neither boxer gave an inch in drawing the capacity crowd of 10,000 to its feet. 

Tecuapetla gave it all he had, but comes up just short in his first career title fight. He heads back to Mexico with his record now at 13-7-3 (10KOs), but head held high in furthering his reputation as a serviceable gatekeeper in the lower weight classes. 

Yaegashi survives the first defense of the title he triumphantly claimed in a throwback performance versus Javier Mendoza last December. Sunday's effort was a far more challenging effort, which didn't appear to be the case on paper. Nevertheless, it's yet another scare that he survives as the three-division champ improves to 24-5 (12KOs).

The 12-round junior flyweight title fight aired live on Fuji TV in Japan, paired up with Naoya Inoue's title defense versus Mexico's David Carmona.

Jake Donovan is the managing editor of BoxingScene.com. Follow his shiny new Twitter account: @JakeNDaBox_v2