Police said the 20-year-old fell backwards and hit his head on the concrete after he was punched in the face on Union Lane shortly before midnight on Sunday.

He had earlier had an argument with the occupants of a white Holden Commodore before one man left the car and hit him.

The violence didn’t end there. 

Police said as members of the public went to intervene they were threatened with a glass bottle.

Police attended but the assailant left the area.

He was last seen on Hunter Street.

The Holden was stopped on Union Lane. A man and woman were arrested but released without charge.

The victim is in John Hunter Hospital in a serious condition.

He suffered a fractured skull.

Anyone with information is urged phone Newcastle City detectives on 4929 0999 or Crime Stoppers on 1800 333 000.