A man suffered a head injury from a push to the floor in Leigh, leaving him hospitalised.
The serious assault happened on Lord Street between around 10.20am and 10.45am on Tuesday April 30.
The victim, a 38-year-old man, got into an argument with the offender when they were outside United Footwear.
During the altercation the offender pushed the victim, forcing him backwards and onto the floor. As he fell, he banged his head on the ground.
While the victim fell unconscious, the offender ran off.
The victim remains in hospital suffering from a head injury.
His attacker is described as being white, in his mid to late 20s, about 5ft 7ins tall and of stocky build. He had short dark brown hair.
He was wearing a grey sports jumper and grey jogging bottoms and spoke with a local accent.
Det Con Lynsey Watson said: “The victim has suffered a serious head injury and we wish to speak to the person that has done this to find out what has gone on. This is a serious incident and we urge anyone with information to come forward.”
Anyone with information is asked to call police on 0161 856 7225 or call the independent charity Crimestoppers anonymously on 0800 555111.