Kenshiro Teraji once again lived up to his ‘Amazing Boy’ ring moniker.

The reigning lineal, WBA and WBC junior flyweight champion turned away a stiff challenge from late-notice challenger Anthony Olascuaga to earn a ninth-round knockout victory. Teraji scored two knockdowns on the night, the latter which produced an immediate stoppage at 1:58 of round nine in their ESPN+/Amazon Prime-Japan main event Saturday from Ariake Arena in Tokyo.

Olascuaga entered the fight as the unlikeliest of challengers. The 24-year-old Los Angeles native—who is only 31 months into his pro career—was training for a flyweight fight on an April 15 show in Osaka when he received the call to replace WBO junior flyweight titlist Jonathan ‘Bomba’ Gonzalez who fell ill. It downgraded the terms of the main event from a three-belt unification bout to a two-belt and lineal championship title defense for Teraji.

The ten-day notice was of no concern to the unbeaten Olascuaga, who went on the hunt early in the bout and landed a right hand down the middle. Teraji took the shot well and charged forward in his first fight since tearing through unbeaten countryman Hiroto Kyoguchi in their November 1 unification bout in Saitama, Japan. The defending champ put in work to the body and also landed in combination upstairs.

Teraji put on a boxing clinic in round two. Olascuaga was game early in the frame but quickly forced on the defensive as Teraji used his jab to set up clean power shots. Olascuaga’s offense dramatically slowed as he fought in reverse while profusely blinking his eye.

A right hand by Teraji landed over Olascuaga’s high guard to begin round three. The visiting challenger responded with a hook that forced Teraji to step back. Olascuaga landed a right hand later in the round but Teraji was able to immediately counter with a counter left hook.

Olascuaga felt confident but his aggression proved costly. A right hand by Teraji rocked Olascuaga and caused his gloves to touch the canvas, which referee Mark Nelson correctly ruled a knockdown late in round three.

Teraji was consistently quicker to the draw in a furiously paced round four. Olascuaga began the frame well intended and eager to rebound from the knockdown but struggled to keep pace. Teraji landed right hands upstairs and continued to target his challenger’s long and lean body.

Olascuaga carried out the instructions put forth by head trainer Rudy Hernandez and launched a body attack of his own in round five. Teraji rode out the brief storm and drove Olascuaga to the ropes. The American boxer kept his hands high and tight but Teraji was still able to split the guard.

The closest there was to a dramatic momentum shift came midway through round six. Olascuaga was still forced to contend with Teraji’s superior body punching but managed to get the champion’s attention with a left hook to the chin. Olascuaga went on the hunt, connecting with a right hand and later with a left hook to the body.

The unbeaten challenger was brimming with confidence as he came out firing at the start of the seventh round. Teraji was driven to the ropes but rediscovered his offensive flow. It came courtesy of deliberate right hands to the body, which affected Olascuaga to the point of a brief clinch. Teraji landed a right hand inside the final minute but Olascuaga stormed back with a series of uppercuts.

The same trend continued in a spirited round eight. Teraji was forced to work for every punch landed as Olascuaga managed to really back nearly every time.

Olascuaga continued to charge forward in round nine. He ultimately ran out of room to work, however. Teraji had the challenger pinned along the ropes and landed a barrage of head shots that eventually drove Olascuaga through the ropes and nearly out of the ring. The bout was immediately stopped, much to the chagrin of Olascuaga (5-1, 3KOs) who dared to be great in just his sixth pro fight.

It ended with his first defeat but in a credible performance that will put more eyes on his continued rise as—at just 24—he has plenty of time to further establish himself as a player at the lower weights.

Meanwhile, Teraji further distanced himself from the rest of the junior flyweight pack.

His place at the top of the mountain was well established in his win over Kyoguchi and once again affirmed in his latest win. Teraji improved to 21-1 (13KOs) and has scored knockout wins in all three bouts during his second title reign.

Teraji regained the WBC title in a third-round knockout of Masamichi Yabuki last March 19, avenging his lone career defeat when he was stopped in the tenth round of their Fight of the Year contender in September 2021. Their first meeting was delayed by 12 days when Teraji previously tested positive for Covid.

In retrospect, he returned to the ring too soon as it showed in his performance that night. He has been a different beast in nearly every other title fight, as he is now 12-1 over his two title reigns.

The hope now is to further unify, though revisiting a three-belt unification bout with Gonzalez could prove problematic.

Gonzalez’s untimely withdrawal left Teraji to take a voluntary title defense while two mandatory challengers wait in the balance. Former titlist Hekkie Budler agreed to stand down from enforcing his position as the top WBC contender but will likely demand a title shot. There is also Cuba’s Daniel Matellon, the WBA mandatory who has been vocal in getting what he feels is an overdue shot.

Still, the end goal for Teraji is to claim undisputed status before gunning for another divisional crown.  

“I woud love to win the WBO and IBF titles in this division,” stated Teraji. “Or I can move up to flyweight and fight for a title there. I have so many choices to consider.

Jake Donovan is a senior writer for BoxingScene.com. Twitter: @JakeNDaBox