Howard Jacobson said it was "beyond belief" to win this year's Man Booker Prize for his novel The Finkler Question.
The author was a 10/1 outsider with some bookmakers but picked up the award and £50,000 prize money at a ceremony at Guildhall, central London.
The Manchester-born writer, who has written 15 novels, said: "I have waited a long time. I don't think I have any right to suppose that I should have won the Booker Prize but I was wanting to win the Booker Prize from the start. I'm not alone in that. All writers feel that, it's such a fantastic prize to win."
Jacobson, who admitted it was beginning to look like he would never win, said he was sick of being described as "under-rated", adding: "It is beyond belief for me because I was so accustomed to being somebody that was, to begin with, not liked by the Booker Prize."
He joked: "The shortlist felt like an embrace, I never expected the affair to be consummated."
The 58-year-old was educated at Cambridge University before spells teaching in Wolverhampton and Sydney, Australia.
The book tells the tale of two old schoolfriends and their teacher and deals with subjects including love, loss, male friendship and what it means to be Jewish.
Discussing his own lengthy career, Jacobson said: "I think I've got better and I've deepened. I never felt I could go near anything truly tragic because I didn't feel anything truly tragic had happened to me. I needed my father to die. He sort of knew that, he sort of said when he was ill, 'I'm giving you something now'."
He described the novel as the saddest he had written and said it had been affected by the deaths of several close friends.
He said: "These things get to you. What I wanted to do though is to feel that I can go on writing an entertaining novel even though the light deepens and darkens and this does become a very dark novel. It is a much darker novel than I thought I was writing."
