Man knocked unconscious in alleged one-punch attack at Gold Coast bar

Newly obtained CCTV shows the moment a man was knocked unconscious in an alleged one-punch attack at a Gold Coast bar in April.

The victim, 57-year-old Steven Johnson, was approached by another man who asked him for cigarettes before allegedly punching him in the head.

In the video, a witness can be seen racing in and grabbing the alleged offender, as security held him down until authorities arrived at Fiddlers Green Bar.

Mr Johnson was unconscious for around 20 minutes after being punched.

Paramedics treated Mr Johnson inside the Surfers Paradise bar before transferring him to hospital. 

He suffered a fractured cheek bone and a haematoma to the back of the head.

Mr Johnson also needed nearly $18,000 in dental work.

Police have charged a 26-year-old former armed serviceman from Brisbane with assault occasioning bodily harm.

He was released on bail but could face up to seven years' jail if convicted.

The case returns to court next week.