Oscar Collazo vacates WBO title, Ryusei Matsumoto elevated to full champion

Puerto Rico’s unified strawweight champion and top-10 pound-for-pound fighter Oscar Collazo has relinquished his WBO belt just hours before a purse bid for a fight with Japan’s interim champion Ryusei Matsumoto.

Matsumoto, 9-0 (4 KOs), has been elevated from interim to full champion at 105lbs.

BoxingScene learned that Japan’s Teiken Promotions was prepared to bid $501,000 for the bout, which almost certainly would have been staged in Japan had Collazo, 15-0 (12 KOs), chosen to accept the defense.

The 29-year-old Collazo, who also reigns as WBA champion, first won the WBO belt in 2023 with a seventh-round stoppage of Melvin Jerusalem.

He made seven successful defenses and, after a flyweight victory in June over replacement opponent Neider Valdez, was poised to fight newly unified flyweight champion Ricardo Sandoval last month in Chicago.

Collazo suffered a rib injury in training and was forced to withdraw from the Sandoval fight. Sandoval subsequently suffered a fifth-round TKO loss to Mexico’s Sergio Mendoza.

The southpaw Matsumoto won the interim belt in late September, defeating Russell Silveira by unanimous decision. His top two contenders are Vic Saludar of the Philippines and his countryman, Jerusalem.