Shocked onlookers have filmed the alarming moment a young man was felled by a coward punch in Brisbane's Fortitude Valley.
The sickening footage, caught on camera by witnesses, shows two men attacking the victim in the early hours of Saturday in the notorious party precinct.
In the video of the callous incident, said to have happened about 4.30am, the assailants round on the victim before one of them lands a punch to back of the head.
The young male victim then crumples to the ground due to the king-hit.
According to Yahoo7, witnesses said the victim didn't want to fight but was accosted by a group of up to six men.
Yahoo reports that bystanders were too scared about their own safety to assist the struck man.
The victim is said to have suffered lacerations in the attack, but not reported it to police.
Police are urging witnesses to the attack to come forward, Channel Seven reports.