Oscar Collazo–Ryusei Matsumoto heads to purse bids after injury halts flyweight move

Oscar Collazo’s WBO mandatory minimumweight title defence against Ryusei Matsumoto will head to purse bids on November 2, with the Puerto Rican now favouring a stay at 105lbs after injury interrupted his planned move to flyweight.

In a notice issued on Monday, the WBO set a minimum acceptable bid of $80,000 for the contest between its world champion and interim titleholder.

The proceedings will take place at the organisation’s headquarters in San Juan, Puerto Rico, on Monday, November 2, at 10am Atlantic Standard Time – 9am US Eastern Standard Time and 2pm in the UK.

WBO president Gustavo Olivieri will conduct the hearing, which will be broadcast live through the organisation’s website and social media platforms.

The purse split has not been announced. For a contest between its champion and interim champion, the WBO calculates the allocation using each fighter’s average purse from their previous three bouts, with neither boxer receiving more than 80%.

The organisation initially ordered negotiations on October 19. A fight date and venue remain unconfirmed.

Collazo favours staying at minimumweight

Collazo had been scheduled to jump two divisions to challenge WBA and WBC flyweight champion Ricardo Sandoval in Chicago on October 10.

However, Golden Boy announced on September 18 that a rib injury sustained in training had forced him to withdraw.

Speaking to Puerto Rican outlet NotiCel last Monday, October 19, Collazo indicated that his attention had returned to minimumweight.

“It’s better to stay at 105lbs to keep pursuing the titles,” Collazo said, translated from Spanish.

He identified January or February 2027 as his intended return window, although no date has been announced for the Matsumoto contest.

Sandoval, meanwhile, remained on the October 10 card against replacement challenger Sergio “Yoreme” Mendoza, who stopped him in the fifth round at Wintrust Arena to capture both flyweight titles.

Mendoza dropped Sandoval twice in the second round and again in the fifth before the referee intervened, ending his reign in his first defence.

Seven successful WBO defences

Collazo, 15-0 with 12 knockouts, won the WBO minimumweight championship from Melvin Jerusalem in May 2023, in his seventh professional fight.

Successful defences against Garen Diagan, Reyneris Gutierrez and Gerardo Zapata followed before his unification victory over Thammanoon Niyomtrong, better known as Knockout CP Freshmart, in November 2024.

Collazo stopped the previously unbeaten Thai in the seventh round in Riyadh, adding the WBA championship and The Ring belt to his WBO title.

He subsequently stopped Edwin Cano Hernandez and Jayson Vayson in 2025. His seventh successful WBO defence came against Jesus Haro in Anaheim on March 14, when Haro’s corner ended the contest after six rounds.

His latest appearance was a second-round stoppage of Neider Valdez on June 20 in Oceanside, California.

Valdez replaced Joey Canoy following visa problems, but the contest became a non-title bout after the replacement weighed 111.2lbs. Collazo scored three knockdowns before the stoppage.

Matsumoto seeks Collazo’s championship

Matsumoto, 9-0 with four knockouts, won the WBO interim title by outpointing previously unbeaten Mexican Russell Acosta at Toyota Arena Tokyo on September 27.

The judges scored the contest 115-113, 116-112 and 118-110 for the Japanese southpaw.

The 28-year-old Teiken fighter previously held the WBA’s secondary minimumweight belt while Collazo remained its Super champion.

Matsumoto won that title against Yuni Takada by fifth-round technical decision in September 2025, then won their March rematch by scores of 120-108 on all three cards.

He relinquished the belt in June, explaining that he wanted to pursue strong opponents beyond sanctioning-body boundaries, before securing his position through the WBO.

The November 2 purse bid will determine promotional rights if the contest proceeds through that process. Matsumoto will seek to turn his interim championship into the full WBO title, with the opportunity to become unified champion if Collazo’s WBA belt is also on the line.