Liverpool's Shaun Caldwell (C), 27, teaches physics by day at the city's Sino-British College then mitts up at night to hit people his own age in the face and ribs. Photo provided to chinadaily.com.cn

White-collars, black eyes

Beijing's fight club

Video: White collar boxing China

Meanwhile, Benis, who also organizes professional bouts for Chinese amateurs, has expanded from hosting WCB events in one Chinese city in 2012 to five cities this year. He plans to stake the flag in two more leading Asian destinations in 2014.

At a training session last week, two American and Asian fighters who had migrated to the sport from Thai kickboxing showed little restraint, attacking each other like bloodhounds.

If their sparring was any barometer, WCB is not Coke Light, it's the full-fat, full-sugar, real deal – a legitimate amateur boxing match scored on a 10-point system. Knockouts are rare. Xiong says there have been two so far in Shanghai, both knockdowns.

Micaelli says many fighters get caught up, or tripped up, by the ego-drenched setting where 500 people, including a fair share of high-rollers and wannabe celebrities, are shouting their name.

"A lot of people like the opportunity to show off – using cool music or throwing down some funky dance moves and bringing hot girls with them into the ring," he says.

"But my style is about staying focused. I'll just walk into the ring more like Mike Tyson style – no socks or robe, nothing flashy, just straight to business."