SHANGHAI - Zou Shiming on Monday vowed to "fight until my last breath" to regain the WBO world flyweight title he lost last Friday when he was knocked out in his first defense of the crown he'd held for just eight months.

China's two-time Olympic gold medalist was a 10-1 favorite to beat No 7-ranked Sho Kimura of Japan, but the 36-year-old looked tired and confused as the fight wore on before the 28-year-old Kimura stopped him at 2:28 of round 11.

Zou, whose professional record now stands 9-2, might be in the twilight of his career but he still wants his belt back.

"I believe in fate, but I am not resigned to it. I will go on fighting until my last breath," he posted on Weibo. "A man must keep fighting to recover what he has lost."

Zou won the vacant title last November in Las Vegas, but since turning professional in 2013 he has largely failed to replicate the dominant form of a hugely successful amateur career that included Olympic gold medals at the 2008 and 2012 Games in Beijing and London.

Zou was sharp in the early rounds against the less experienced Kimura (15-1-2), a part-time beer-truck driver, but the Japanese upstart refused to be put off by a nasty cut above his right eye in the sixth and gradually wore down Zou with relentless pressure and accurate punching.

Kimura unleashed a flurry of eight punches late in the 11th that sent Zou crashing to the to the canvas.

Zou, who was promoting himself for the first time after parting with US company Top Rank, was left in tears in the ring at the Shanghai Oriental Sports Center.

His wife Ran Yingying, a former television presenter who is heavily involved in her husband's new promotion company, posted a message to Zou on Weibo early on Monday.

"At dawn I heard a steadfast pledge. I also want to say: I believe in you, and I know you," Ran wrote.

"Restore what has been lost! A sincere man keeps fighting."

Agence France-Presse