By Jake Donovan

Kazuto Ioka made the first successful defense of his flyweight title, cruising to a virtual shutout of Argentina's Roberto Domingo Sosa over 12 rounds Sunday evening at home in Osaka, Japan.

Scores were 119-109 (twice) and 120-108 in favor of Ioka, who was in control every step of the way.

Even before the opening bell sounded, Ioka already knew what lied ahead in his immediate future. Barely seven hours prior, Juan Carlos Reveco—the former long-reigning champion whom Ioka defeated to win the flyweight title in April—won a 10-round decision at home in Argentina to preserve their mandated rematch. 

Whether on the back of his mind or simply just that focused on the task at hand, Ioka took it out on Reveco's countryman, as Sosa was in way over his head in just his second career fight outside of Argentina. There were several moments in the fight where Ioka appeared well on his way to a stoppage, but could never land that one final blow to put away his challenger. 

Credit goes to Sosa as well for braving the storm and never quitting. His corner gave him an earful several times in between rounds, but collectively reached a point where they knew he stood little chance of pulling off the massive upset.

As his knockout power has not followed him up the scales, Ioka put his entire arsenal on display in what became a 12-round workout. He was particularly effective with left hooks to the body and power punches upstairs, barely conceding the during any given exchange as he never settled for just boxing his way to victory.

His efforts were well-reflected on the final scorecards, all overwhelmingly in his favor. Ioka improves to 18-1 (10KOs) with the win, his fourth straight. 

Sosa fall to 26-3-1 (14KOs), with all four blemishes coming in the span of his past six fights. The bout was his second failed bid at a major title, having dropped a 12-round decision to Juan Carlos Sanchez Jr. in their June '13 bout in Las Vegas. 

Ioka won the flyweight title on his second try in April, outpointing Reveco over 12 hard-fought rounds. The win came just shy of a year following the lone loss of his career, a 12-round split decision to unbeaten Amnat Ruenroeng who should have won by far more than what the final scores read. 

The loss delayed Ioka's hopes of becoming just the second fighter ever from Japan to win world titles in three weight classes. He cut his teeth as a strawweight champ, winning the belt in just his 7th pro fight with a knockout win over then-unbeaten Oleydong Sithsamerchai as part of a Fighter-of-the-Year level 2011 ring campaign.

His strawweight title reign ended with a 12-round win over Akira Yaegashi in their savage June '12 bloodbath, a fitting scenario for what was the first-ever title unification fight between reigning champions from Japan. Both fighters moved up in weight, with Ioka adding the junior flyweight title in 2012 and eventually the flyweight crown to his resume.

Following Sunday's win over Sosa, Ioka insisted he will strive to face the best in the division. Long-term, that would mean a long-awaited showdown with World flyweight champion Roman 'Chocolatito' Gonzalez, who next defends his crown versus former two-divsion champ Brian Viloria in October at Madison Square Garden in New York City. 

The careers of Ioka and Gonzalez somehow ran parallel for years, with the two never managing to secure a showdown despite being in direct line of one another. Instead, both have enjoyed separate title reigns through three weight classes, though now insist a future clash is inevitable.

In the meantime, Ioka plans on returning to the ring by year's end. A strong possibility is his fighting on New Year's Eve at home in Osaka, which has been the case for each of the past four years since beginning the tradition in 2011. 

If so, it will have come versus Reveco, who earlier in the summer successfully lobbied for a mandatory rematch based on the close nature of their first fight and his standing as a longtime champion before losing his crown. 

Ioka-Sosa aired live on TBS-Japan as well as Argentina TyC Sports. 

Jake Donovan is the managing editor of BoxingScene.com.
Twitter: @JakeNDaBox
Facebook Page: JakeBScene