The little-known Size, with his group Reprazent, scooped the prestigious Mercury Album of the Year title with New Form.
Pop, rock, dance and contemporary classical were all represented in the eclectic shortlist of 10 artists.
Reprazent is a Bristol-based collective consisting of Krust, DJ Die Suv, MC Dynamite, vocalist Onallee and Size. Their roots are a diet of Studio One reggae, Seventies funk and soul and rare groove, Eighties hip-hop and Nineties backbeat rave.
Size, who attended the award ceremony at the Grosvenor House Hotel in central London, with his band, said: "A lot of people have supported us and I thank them. People said we were crazy, but we believed what we were doing. We all have been working hard for this, this is not just about me."
The pounds 25,000 prize, in its sixth year, is intended to celebrate the best 10 albums of the past year. Announcing the winner, the chairman of the judges' panel, Simon Frith, music critic and Professor of English Studies at Strathclyde University, said: "We have been arguing for quite a long time. We do think that Radiohead's album is a classic, but in the end we all agreed it was to be Roni Size's New Form.
"The decision came down to the two bands after five hours' deliberation. The Spice Girls were involved until surprisingly late in the process, but in the end we are not comparing like with like. It was a majority decision for Roni Size. It was the record we were most happy to tell buyers this is the one to go out and buy."
Earlier yesterday Radiohead toppled the Prodigy as favourites to win the award. Their release OK Computer had odds of 11-8, the Prodigy's The Fat of the Land was second favourite at 9-4 whereas Size was 16-1. The award, dubbed the Booker Prize of music, was hosted by Jools Holland. The shortlist was selected from a record entry of 155 albums by British and Irish artists. Other artists who did not make the grade included Beth Orton, Suede, Mark-Anthony Turnage and the Chemical Brothers.Reuse content