A man sustained serious internal injuries, broken ribs, a fractured right shoulder and bruising in what police have described as an unprovoked attack in East Yorkshire.
Three men approached the man, aged 47, in Belgrave Road, Bridlington, on Thursday evening and asked him for a cigarette.
As he walked off he was assaulted from behind and knocked unconscious.
He was taken to hospital and is said to be in a stable condition.
One of the suspects has been described as mixed race, in his early 20s and 5ft 7in (1.7m) tall. He was wearing a dark blue jacket.
Police have appealed for witnesses.