A man suffered a fractured skull after he was struck in the head by an exhaust pipe.
The 40-year-old man was viciously assaulted with the weapon at about 11pm on Saturday 22 November 2014.
The man and his friend were walking along Gerard Street, Ashton-in-Makerfield, Wigan, when a man in a Honda Civic pulled up alongside and got out.
An altercation broke out which resulted in the 40-year-old being punched to the floor, before a number of members of the public intervened and separated the two parties.
The victim then got up and he and his friend walked away, while the driver got back into his car and seemingly drove away from the scene. However, he then pulled up on Princess Street and confronted the victim and his friend again.
This time, he took a car exhaust from his boot and swung the piece of metal at the victim. The man managed to block the first swing but the second connected with the back of his head, knocking him to the floor.
Police arrived at the scene within minutes and a 21-year-old man was arrested on suspicion of section 18 assault. He was later bailed pending further inquiries.
The 40-year-old man suffered a fractured skull as a result of the incident.
Officers are now appealing to anyone who witnessed either incident to come forward.
Detective Constable Rachel Forsythe said: “It is unclear why this incident escalated to the level of violence it did, but what is clear is that the victim suffered serious injuries – including a fractured skull.
“In some ways he is lucky his injuries were not more serious as he was struck with some force with a car exhaust with jagged edges and could have suffered even worse injuries.
“I am appealing for anyone who either witnessed one or both of the assaults, or those members of the public that intervened in the first incident, to come forward.
“If you do have any information it could be crucial to our inquiries so please if you either witnessed what happened or know something then please come forward and speak to us.”
Anyone with information is asked to call police on 101 or the independent charity Crimestoppers, anonymously, on 0800 555 111.