Electronic artist James Blake has won this year's Barclaycard Mercury Prize with his second album, Overgrown.
"Well, I lost the bet," Blake said after beating bookies' favourite Laura Mvula and stars like David Bowie and Arctic Monkeys to the £20,000 prize.
Judges called his record "inventive, poetic and poignant", adding "James Blake makes music like no-one else".
The Mercury Prize, for the best British or Irish album of the year, was handed out at the Roundhouse in north London.
In a brief acceptance speech, Blake thanked his parents "for showing me the importance of being self-sufficient".
Speaking backstage, the 25-year-old said he felt "jubilant and confused".
"This is the first award I've ever won apart from a tennis trophy I won when I was 12," he said.
Blake's album Overgrown, which was released in April, got to number eight in the UK chart.
Asked how it felt to beat Bowie, he replied: "I don't think I beat him.
"A lot of people do their best work when they're young - and it's always disappointing when they don't keep going and don't keep innovating. So David Bowie's an inspiration to people like me."
He added: "I feel like I deserved it as much as anyone else did."
The singer-songwriter had previously been nominated for the Mercury Prize in 2011 for his self-titled debut album.
A classically-trained pianist who studied popular music at Goldsmiths University, Blake emerged from the dubstep scene.
But his cerebral, ambient compositions have little to do with the genre he has since dismissed as "testosterone-driven" and "macho".
However, reaction to his win was muted.
Many in the audience had expected soul newcomer Laura Mvula to take the prize, for her inventive, heartfelt album Sing To The Moon.
There was also strong support for Sheffield's Arctic Monkeys, whose fifth album, AM, has received across-the-board praise from critics.
The band, who won the Mercury for their debut in 2006, said they did not expect to win.
Frontman Alex Turner added that the prize was a "huge accolade", which can help "artists at different stages of their careers".
Mvula was happy with the result, telling the BBC "the nomination itself felt like an award".
"I feel like the new girl," she added. "I don't feel like I deserve anything."
Dance acts Disclosure and Rudimental, as well as Nottingham teenager Jake Bugg, were also on the shortlist.
Folk band Villagers, female punk group Savages, Oxford rockers Foals and dance musician Jon Hopkins rounded off the 12 nominees.
Most of the artists took to the stage to perform a track from their shortlisted albums, but David Bowie and Laura Marling did not attend.
Both sent specially recorded videos, and Bowie's self-shot film of the song Love is Lost cost just $12.99 (£8) to make - the price of the USB stick he bought to send out the finished clip.
Established in 1992, the Mercury Prize has been won by albums such as Pulp's Different Class and Primal Scream's Screamadelica.
But the judges, who remain anonymous until after the prize-giving ceremony, can be unpredictable.
In 2009 the prize went to little-known rap artist Speech Debelle. Even her record company was taken by surprise and failed to get enough copies of the album into shops to capitalise on the resulting publicity.
This year, notable albums by London Grammar and My Bloody Valentine failed to make the list, with the latter band complaining bitterly about their exclusion.
In an interview with the Guardian, frontman Kevin Shields said their critically lauded release mbv had failed to meet eligibility criteria because the band had sold it exclusively through their own website.
"Our album's not a real album because it's independent," he said. "The corporateness has got to such a point where we've essentially been told that we don't exist."
This year's nominees were whittled down from a long list of 220, submitted to the jury by their record labels.
The 12-strong shortlist had been criticised for being too mainstream, with five number ones and seven former nominees among the competitors.
Blake, whose album had only sold 27,000 copies before the ceremony, is likely to enjoy a significant boost.
The Official Charts Company said Rudimental, Jake Bugg and Disclosure had already benefitted, selling more than 23,000 copies apiece since nominations were announced last month.