Trailblazer Zou Shiming struck a thunderous blow for China when he won his country's first Olympic boxing gold at the Beijing Games and has again chosen national glory over the lure of professional riches to defend his title in London.

Zou clinched the light flyweight title when Mongolia's Purevdorjin Serdamba threw in the towel early in their bout due to injury, while Zou overcame Belfast's Paddy Barnes in the semi-finals in China.

His victory may have lacked the romance of compatriot Liu Xiang's 110 metres hurdles win at the 2004 Athens Games but the pint-sized Zou was nonetheless feted as a hero at home for his triumph in a "foreign" sport that had long chewed up and spat out China's elite boxers.

Zou, the son of a factory worker and a kindergarten teacher in the backwater province of Guizhou, has further enamoured himself to home fans and officials with his decision to step into the Olympic ring once more.

"I am a highly ambitious man," he told state broadcaster CCTV. "All of these Asian, world or Olympic gold medals, whatever China hasn't got, I want!"

Following Beijing, Zou's drive saw him win gold at the 2010 Asian Games on home soil in Guangzhou and a third world title at Baku last year.

The 31-year-old will head to London one of the most favoured fighters in his division, but his achievements are a far cry from his downtrodden boyhood, when he was too scared to tell his mother about his love of the ring.

Zou describes himself as a "weak child" who was bullied not only by boys, but also by girls. He can point to a scar that one terrifying schoolgirl scratched into his face.

His mother coddled him, and sometimes dressed him in girl's clothes and tied his hair into pig-tails.

He was pushed into wushu, China's gymnastic martial art, but rebelled and began boxing training in secret at school.

The martial arts training stuck, however, and Zou credits it for giving him the speed and lightning reflexes that offset his relatively short reach, allowing him to counter-punch and steal points off more powerful opponents.

Zou's style, honed with his long-time coach Zhang Chuanliang, was derided by opponents' coaches early in his career, but is perfect for amateur boxing bouts where knockouts are rare and point-scoring is paramount.

"People overseas say I fight like a pirate ... or like a martial arts fighter in a novel," Zou, who also took bronze at the Athens Games, told CCTV.

Others see shades of his hero Muhammad Ali in his dancing footwork and his habit of letting his gloves fall to his waist when he backs away from opponents, tempting them to take the money-shot at their peril.

While perhaps sharing some of Ali's showmanship, the softly-spoken Zou displays none of the heavyweight great's trash-talking bravado and is content to let his fists do the talking.

"I have confidence, because after all, my technique is up there with the world's best, but it's going to be very, very tough (at London)," Zou told state media.

"There will definitely be a lot of opponents focusing on me especially. Also, this will be my third Games and I'm getting on in years, that doesn't help.

"But at the same time, there aren't many competitors there who will have my big-tournament experience."