The 28-year-old Kimura suffered a cut eye as early as the third round – from an accidental head butt – and needed medical attention in the sixth but he fought on doggedly, delivering his payload late in the 11th round.

The Japanese had Zou backed up against the ropes before he went for the kill, landing a good right hook before a furious left-right combination staggered Zou.

The Chinese star then crumbled with exhaustion. Zou failed to get up and Filipino referee Danrex Tapdasan didn’t bother even to count as the audience stood in stunned silence.

Officially, the bout was marked as a technical knockout victory with the stoppage coming two minutes and 28 seconds into the 11th round.

The 36-year-old Zunyi-born Chinese fighter eventually got up – after a full minute – and after Kimura rushed to his corner to offer his help. A tearful Zou hugged his wife, Ying Ying Ran, who stood in shock disbelief. He grabbed the microphone before making what could be the longest post-fight speech in history.

This one’s for mum, says ‘poor’ Sho Kimura ahead of world title showdown against Zou Shiming

“Even though I couldn’t win this fight, I will continue to fight on,” said Zou, whose record dropped to 9-2-0 with two knockouts. “I must thank the audience here. You have supported me all the way through. China is a big country. I am sure I will come back. I’m the king forever!” he said defiantly.

“I am worried my parents are worried. I hope they don’t worry about my injuries.”

Zou’s immediate future has been thrown in jeopardy with his latest loss. At 36, he decided to promote the fight on his own, a move that probably backfired – and he might not get another crack at the world title given his advanced age.

How China boxing star Zou Shiming has infuriated his business partners by going it alone

Zou won the belt last November in Las Vegas against Thailand’s Prasitsak Phaprom and was making his first title defence.

“I have been boxing for 22 years. Boxing has never been understood by others in China. I have won the world title and won two Olympic gold medals. Why do I still stand here?” Zou told the stunned audience. “Althought I lost, I drew attention to the boxing game to millions of people in China. I think it was worth it.”

Zou started off confidently, landing punches almost at will, but he dropped his hands throughout the fight and lacked the conditioning to last the 12 rounds. The Chinese star was a spent force in the 11th round as Kimura kept piling forward before staging his stunning victory. Zou just couldn’t keep up with the pace and ran out of gas in the end.

Meanwhile, Kimura, who improved his record to 15-1-2, delivered on his promise by winning in honour of his late mother, who died when he was just 20 years old.

Zou Shiming infuriates business partners by going it alone

Kimura, who worked part-time delivering crates of beer in a Tokyo restaurant, said during the build-up to the fight that he was so poor he couldn’t even “afford to buy a new pair of training shoes”.

But Kimura is now world champion at his first attempt and he’s expected to move from rags to riches in a fairy tale ending that will make him a hero he’d been dreaming of once he returns to Tokyo on Saturday.