This was the sickening moment a Thai man knocked out an Australian pensioner with a vicious punch in a road rage argument.

Expat Colin Gerrard, 72, had been collecting his eight-year-old daughter from school last October at around 4pm in Pattaya, Thailand in this video from the Newsflare archive.

He claims that he indicated to turn right but local driver Sumet Rungratanapan, 28, tried to overtake as he pulled out - causing a minor scrape.

The two men then squared up in the middle of the street when Colin produced a machete from inside his car, which he admitted to and was pictured on his front seat, and allegedly smashed the Thai man's car window.

The dispute is filmed as each party tells officers and reporters their version of events.

Then with a traffic policeman standing between them, they then carry on arguing with enraged Sumet yelling 'I have a clip' as his wife stands next to him saying 'how dare you'.

But Sumet then unexpectedly takes a run-up and throws a powerful left hook - instantly knocking out Colin who falls backwards onto the ground.

The Australian was out cold for around a minute then came round in a daze with blood pouring from his left eye and onto his shirt as his daughter stands crying.

The entire punch-up was filmed by a reporter who attended the initial traffic dispute.

Police Lieutenant Colonel Nakhonrat Nonsilad said: Neither man has been charged. We have to wait for the interrogation of both parties.''

This is the sickening moment a Thai man knocks out an Australian pensioner with a vicious punch in a road rage argument.