A random act of senseless violence left a young man in hospital and his two friends distraught during a night out in Wollongong's CBD.
Police said the 18-year-old was walking along Keira Street around 12.30am on Sunday morning when a passer-by made insulting comments.
When the victim ignored the stranger, he was king hit - leaving him with a concussion, broken nose and cuts to his face.
A puddle of blood now marks the site, and someone has scrawled "king hit" and the date in chalk on the footpath.
A police spokeswoman said the attack appeared to be random.
"The victim has ignored the aggressor and continued walking in a northerly direction," she said.
"The person of interest has turned, following the victim and has swung a punch to the nose."
The spokeswoman said the man's friends helped him to his knees while the aggressor fled.
The father of one of the victim's friends, who did not want to be identified, said the incident had left him feeling concerned about how people could commit "such violent acts".
He said the amount of random violence had increased since he was young.
"It just seems far more prevalent now," he said.
A passing police patrol car arrived at the scene just moments after the incident occurred.
Statements have been taken from witnesses and police have reviewed nearby CCTV footage. However, the incident was not captured on camera.
The victim was taken to hospital and discharged several hours later.
Wollongong police are now calling on anyone who saw the incident to come forward.
The aggressor is described as being aged around 20, Mediterranean or Middle Eastern in appearance, 170 centimetres tall, and of solid build.
He was wearing a tight-fitting white shirt with dark jeans.