Ryusei Matsumoto Outpoints Acosta Silveira to Win WBO Interim Minimumweight Title in Tokyo

Ryusei Matsumoto stayed unbeaten and picked up a new belt in Tokyo on 27 September 2026, outpointing previously undefeated Mexican Russell Acosta Silveira over twelve rounds to win the vacant WBO interim minimumweight title on the Takuma Inoue vs Tenshin Nasukawa card at Toyota Arena Tokyo.

A Unanimous Verdict at Toyota Arena Tokyo

The fight went the full twelve rounds, and all three judges had Matsumoto in front. Fightnews.com, in a report by Joe Koizumi, listed the scores as 118-110 from Tim Cheatham, 116-112 from Ellis Johnson and 115-113 from Patrick Morley. Roberto Ramirez Jr. of Puerto Rico refereed, and the show was promoted by Teiken Promotions.

The win lifted Matsumoto to 9-0 with four knockouts. Acosta Silveira arrived 17-0 with six stoppages and left 17-1, his first defeat as a professional. Fightmag noted that it was the third bout of the evening, after Tomoya Tsuboi's fight and before Sam Goodman's IBF interim super bantamweight contest. The event was shown on Prime Video in Japan and on DAZN in the United States and other selected markets.

Speed Against Single Shots

According to Koizumi's ringside account, the 28-year-old southpaw relied on quicker hands and combinations, landing to the head and to the body and moving enough that his opponent struggled to set his feet. The Mexican did land the heavier individual punches at times, and the report singles out the fourth and seventh rounds as the sessions in which he connected cleanly. It was not enough to change the pattern. Matsumoto kept scoring in bunches round after round, and the wide gap on one card against the two-point margin on another shows that at least one judge saw the middle rounds as more competitive than the overall result suggests.

Matsumoto weighed 105 pounds, the division limit. Fightnews gave Acosta Silveira's weight as 104.75 pounds.

From WBA Regular Champion to WBO Contender

The new belt is not Matsumoto's first. He was born in Takasago, Hyogo Prefecture, on 14 May 1998 and turned professional in February 2023 with a third-round knockout of Erson Trinidad at Korakuen Hall. Boxing News reported that he came into the paid ranks with an amateur background of 92 bouts. He fought six times at Korakuen Hall before moving to bigger arenas.

In his seventh pro fight, on 14 September 2025 in Nagoya, he challenged Yuni Takada for the WBA "regular" minimumweight title. An accidental clash of heads in the fifth round left Takada unable to continue, and Matsumoto took a technical decision. Boxing News gave the scores as 50-46, 50-45 and 50-45. The same report noted that the bout came during a hard year for Japanese boxing after several fatal ring injuries, and that Matsumoto wore the name of his late friend Shigetoshi Kotari on his trunks.

The rematch, held in Yokohama in March 2026 according to Wikipedia's record of his career, removed any doubt. Fightnews reported a 120-108 shutout on all three cards, with Takada cut by counters in the seventh round and bleeding for the rest of the fight. Matsumoto later gave up the WBA regular belt, which made him available for a WBO title.

Why the Belt Is Interim

The full WBO minimumweight title still belongs to Puerto Rico's Oscar Collazo, who also holds the WBA "super" and Ring Magazine belts at 105 pounds. Wikipedia reports that Collazo announced a move to flyweight after stopping Neider Valdez in two rounds on 20 June 2026, and that he is scheduled to challenge WBA and WBC flyweight champion Ricardo Sandoval in Chicago on 10 October 2026.

With the full champion fighting two divisions higher, the WBO interim title was contested in Tokyo, and Matsumoto now holds it. If Collazo stays at flyweight and gives up the 105-pound title, Matsumoto is the obvious candidate to be elevated or to fight for the vacant full belt. If Collazo returns, a fight between the two unbeaten southpaws would be the natural next step. Neither side has officially announced a plan, and the sources consulted for this report do not include any comment from Matsumoto on what comes next.

A Busy Night for Japanese Boxing

Matsumoto's win was one of several title bouts in Tokyo that evening. In the main event, Takuma Inoue got up from a seventh-round knockdown to beat Tenshin Nasukawa again and keep his WBC bantamweight title, while Australia's Sam Goodman won the IBF interim super bantamweight title against Ryosuke Nishida. With so much happening on one card, the minimumweight fight drew less attention than it deserved, but it leaves Japan with an unbeaten 105-pound titleholder whose next move depends partly on what Collazo does in Chicago.

Sources

• Matsumoto Defeats Acosta, Wins Interim WBO 105lb Belt (Joe Koizumi), Fightnews.com, September 2026
• Live results: Inoue beats Nasukawa in rematch to retain title, Fightmag, 27 September 2026
• Takuma Inoue recovers from knockdown to repeat win over Tenshin Nasukawa, Yahoo Sports, 27 September 2026
• Matsumoto wins WBA minimumweight belt as Takada injury halts fight (Shaun Brown), Boxing News, September 2025
• Matsumoto Beats Takada, Keeps WBA 105lb Belt (Joe Koizumi), Fightnews.com, 2026
• Ryūsei Matsumoto, Wikipedia, accessed 3 October 2026
• Oscar Collazo (boxer), Wikipedia, accessed 3 October 2026
• Boxing title bouts archive, September 2026, BoxingTitleFights.com, accessed 3 October 2026