Author Alan Hollinghurst has won the 2004 Booker Prize for his novel, The Line of Beauty.
Hollinghurst had been previously shortlisted for the Booker prize
The prestigious award is for the best novel of the last 12 months by an author from a Commonwealth country or the Republic of Ireland.
Also nominated were Achmat Dangor, Sarah Hall, Colm Toibin, Gerard Woodward and bookies' favourite David Mitchell.
Hollinghurst, 50, takes home a cheque for £50,000.
The winner was announced by chair of the judges, MP Chris Smith, at a ceremony in the Royal Horticultural Halls in Westminster, central London.
Bitter Fruit - Achmat Dangor
The Electric Michelangelo - Sarah Hall
The Line of Beauty - Alan Hollinghurst
The Master - Colm Toibin
I'll Go To Bed At Noon - Gerard Woodward
Cloud Atlas - David Mitchell
In accepting his award, Hollinghurst said: "It's very amazing to me that the long, solitary process of writing a novel should lead to a moment like this.
"I hardly know where I am. My whole psychological technique for dealing with this
evening was to convince myself I wasn't going to win it.
"I know it's a decision I shall be grateful [to the judges] for for the rest of my life. How they reached it, I've no idea and I'm conscious how easily it could have gone to one of the other authors."
The Line of Beauty is about Oxford University graduate, Nick Guest, living in the London house of a high-flying Conservative parliamentarian at the height of Margaret Thatcher's power.
Set in the boom years of the 1980s, Guest has a passionate affair with a black council worker before falling in love with a cocaine-addicted millionaire.
Mr Smith said: "This year's shortlisted authors... have indeed written formidable books. They were all strong contenders.
"This was an incredibly difficult and close decision."
Mr Smith said the final decision was between the "big three" of Hollinghurst, Mitchell and Toibin.
He added: "It was down to a very difficult decision between three books... but all six of them were in contention right at the start."
The judging panel included novelist Tibor Fischer, writer and academic Robert Macfarlane and Erotic Review editor Rowan Pelling.
Martin Higgs, the literary editor of Waterstone's, said: "Hollinghurst's The Line of Beauty is a wonderful book, a sophisticated social comedy with huge dollops of tragedy set against Thatcher's Britain and the rise of AIDS.
"Hollinghurst has previously been known to a literary audience and particularly to a gay audience so I am delighted that this prize will help elevate his writing and give it a much wider appeal, something he richly deserves."