Jamie Pettman of Belgrave Road in Dover, was sentenced for grievous bodily harm at Canterbury Crown Court after he admitted assaulting a 16-year-old boy.
The teenager was waiting for his friends outside a shop in Worthington Street before being approached by two men.
19-year-old Pettman ran at the young man and hit him on the side of the head, resulting in the victim sustaining a serious head injury.
The 16-year-old was transferred from the William Harvey Hospital to Kings College Hospital where he underwent emergency surgery for his injury.
