Barely three days removed from his United States training camp, Marlon Tapales kicked off the sparring stage of his Baguio City buildup and left his trainers convinced that he is on the right track towards the 26 December unification clash with Naoya Inoue.

"He did great in his first sparring (session)," reported lead strategist Ernel Fontanilla from the City of Pines.

Tapales, the country's only current world boxing champion, will bring his World Boxing Association and International Boxing Federation straps to the Ariake Arena in Tokyo.

Inoue is likewise dangling his World Boxing Council and World Boxing Organization belts in a four-belt showdown that will produce an undisputed 122-lb champion by yearend.

Rising bantamweight prospect Herlan Gomez leads the cast of sparring partners in Baguio City and he will soon be joined by Pete Apolinario, Vincent Astrolabio and possibly a pair of amateur standouts in Tokyo Olympics silver medalist Carlo Paalam and Ian Clark Bautista.

Baguio City will serve as Tapales' home right until his departure for Tokyo sometime in the third week of December.

The initial phase of Tapales' preparation took place at the Knuckleheads Gym in Las Vegas where he also racked up quality sparring with Filipinos Jonas Sultan, Jade Bornea and visiting fighters.

Tapales, who briefly reigned as world bantamweight champion, had won the WBA and IBF jewels after beating Murodjon Akhmadaliev of Uzbekistan last April in San Antonio, Texas.

Inoue, nicknamed 'Monster', winner of four world titles in as many weight classes, knocked out American Stephen Fulton to seize the WBC and WBO crowns last July in Tokyo.

Tapales parades a 37-3-0 win-loss-draw record with 19 knockouts while Inoue totes a 25-0-0 card with 22 knockouts.

Given his sterling credentials, Inoue has been installed the heavy betting favorite.