This is the satisfying moment a pervert who patted a woman's bottom suffered instant karma when he was knocked out by her boyfriend.

CCTV footage shows the woman and her partner closing up their shop when a passer-by approached and slapped her backside as she bent over to roll up artificial turf outside a cannabis dispensary.

The man then sauntered away but the woman's furious partner gave chase, unleashing a powerful strike that sent him sprawling on the pavement.

The man was left out cold in the motorcycle parking area in Pattaya, eastern Thailand.

She said: 'He deserved that. Women should be able to stand in the street without being assaulted.'

The grabby holidaymaker recorvered and walked away without police getting involved.

Former fishing village Pattaya became popular with American troops on 'rest and relaxation' breaks in the 1950s and 1960s when the U.S. military had bases in Thailand while fighting Communism in Vietnam. Rural families are said to have even dressed their sons as women to cash in on the gold rush.

The handful of bars in the coastal town quickly grew and it is now the world's biggest sex holiday destination, with round-the-clock prostitution and drugs - a modern-day Sodom and Gomorrah rife with crime and debauchery.

Government chiefs have attempted to clean up the city but regular violence, depravity and claims of corruption continue to blight its reputation.