Hiroshige Osawa suffered a seventh-round technical knockout on Saturday in his WBO featherweight title fight against undefeated Mexican champion Oscar Valdez.
The 31-year-old Osawa, in his first world championship bout, looked stiff at the start of the fight and was knocked down in the fourth at the Thomas & Mack Center. Osawa was battered in the seventh, when the referee stopped the fight. His record fell to 30-4 with four draws and 19 wins by knockout.
"This was due to my lack of ability," Osawa said. "My only feeling is one of frustration. Because I lost, there's nothing I can say."
The 25-year-old Valdez improved to 21-0 with 19 of his wins coming via the knockout.
The bout was on the undercard of Manny Pacquiao's ring return.