A brave bar owner beat up a Russian tourist after he refused to pay his tab.

Jane, 53, slapped the reveller, identified only as 'Michel', when he tried to dodge the paltry bill at her shop in Thai 'sin city' Pattaya, Thailand, on January 13.

Cops arrived at the scene after receiving reports about a fight at 2:30 am local time.

They found the bloodied Russian man knocked out on the ground with wounds on his face. He received first aid from responders, but declined to go to the hospital.

Jane claimed she was acting in self-defense, saying the tourist slapped her when she tried to collect the payment for the alcoholic drink he had ordered worth 60 THB (around 1.82 USD).

An unnamed bar employee told local reporters: 'He looked drunk before. It was difficult to understand him while he was ordering.'

She added that the man's mood was sour after he had failed to pick up a woman in the shop.

Police have brought both parties in for questioning. They also gave Jane a warning, telling her that the violent incident could affect the city's tourism and reputation.

The case is being handled according to proper legal proceedings, investigators said.

Military top brass from Bangkok have been trying for several years to clean up the notorious 'sex capital' of the world - branded a modern-day Sodom and Gomorrah - to turn it into a family-friendly resort.

However, they face an uphill struggle against its entrenched 24-hour sex industry and endemic corruption that allows it to continue unabated. The bars - which function as shop windows for prostitutes - along with massage parlours and street workers are also a lucrative part of the tourism industry, which before the pandemic accounted for 21 percent of Thailand's annual GDP, generating 1.8 trillion baht (52.3 billion USD) in revenue.