By Jake Donovan

Ken Shiro remains an unbeaten titlist—and arguably the best junior flyweight in the world. 

The 27-year old from Kyoto, Japan registered the sixth defense of his 108-pound crown, dropping and stopping Philippines' Jonathan Taconing in four rounds Friday evening in Osaka, Japan. 

A right hand shot dropped Taconing, separating the southpaw challenger from his senses as the fight was waved off at 1:00 of round four. 

Traffic ran largely one-way in the ESPN+ livestream chief support, with Shiro establishing distance early through his potent jab. Both boxers were in the ring for the first time in 2019, though Taconing endured the far longer layoff having not fought since a 12-round win last September. 

Shiro, who was last seen in a 12-round nod over Saul 'Baby' Juarez last New Year's Eve, fought at his desired pace in the opening round but was slightly forced out of his comfort zone in round two. Taconing stepped up the pace, scoring with occasional body shots while applying pressure in hopes of scoring a big road win. 

That never came close to happening, although a headbutt in round three threatened to produce an anti-climactic ending to their title fight. A clash of heads is hardly uncommon in fights between orthodox and southpaw boxers, with the two colliding at close quarters midway through round three. Taconing was slightly off-balance, cupping his right hand behind Shiro's head and inadvertently pulling him forward. 

The sequence left Taconing with a cut over his right eye. Because of an outdated and absurd rule in place with the World Boxing Council (WBC)—whose title was at stake—Shiro was deducted a point as the unaffected fighter, despite the fact that the challenger's actions caused the infraction. 

It rendered moot, as Shiro regained his composure and proceeded to close the show. An aggressive pace came of the fourth round, too much so for Taconing who was wild with a left hand badly missing its mark. Shiro saw the shot coming, dipped back his head and repositioned his stance to maximize leverage on a right hand which landed flush on the challenger's chin. Taconing pitched face forward to the canvas upon impact, his reaction not sitting well with referee Frank Garza, who immediately halted the contest. 

Taconing (28-4-1, 22KOs) came up well short in his third bid at a major title, having dropped decisions to Thailand’s Kompayak Porpramook in May 2012 and to Mexico’s Ganigan Lopez in July 2016. Both fights took place in his opponent’s home country, as did a 10th round knockout of former titlst Ramon Garcia in April 2015, the lone road win of his 12-year career.

The 32-year old Filipino entered Friday’s bout having won his last six starts since his title fight loss to Lopez. The end result is the first stoppage loss of his career.

Meanwhile ,Shiro (16-0, 9KOs) remains unbeaten and still champion.  The win extends his reign which began with a 12-round majority decision over Lopez—their lone common opponet—in Dec. 2017. Their rematch last May was considerably more decisive, with Shiro scoring a 2nd round knockout to kick off a 2018 campaign where he scored three wins over former titlists, having also turned away the challenges of Milan Melindo and, most recently, Mexico’s Saul Juarez last December.

The run helped earn him accolades as, unofficially, the best junior flyweight in the world today. Friday's result certainly didn't detract from that argument. 

The title fight aired in supporting capacity to the middleweight title fight rematch between Rob Brant and Ryota Murata. 

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