Author Lloyd Jones has won the Wales Book of the Year for his second - and surreal - novel, entitled Mr Cassini.
Lloyd Jones was praised for his surreal humour
The book, described by Jones himself as an "anti-novel", was chosen over poetry by Christine Evans, and essays by rock climber and travel writer Jim Perrin.
Llwyd Owen was revealed as the winner of the Welsh Book of the Year at the Hilton Hotel ceremony in Cardiff.
Both winners will each receive £10,000, with two runners up receiving £1,000 each.
In Jones's Mr Cassini, the reader is taken on a journey through a man's "troubled mind as he tries to recover the lost years of his childhood".
It is said to be a novel of many themes, including monsters, snow, drugs and rainbows.
Christine Evans Growth Rings
Lloyd Jones' Mr Cassini
Jim Perrin The Climbing Essays
T Robin Chapman Un Bywyd o Blith Nifer
Gwen Pritchard Jones Dygwyl Eneidiau
Llwyd Owen Ffydd Gobaith Cariad
During the shortlist announcement at the Hay Festival, Powys, in May, it was described as making "brilliantly surreal use of humour, highly expressive and readable."
Jones said it gave a "nod" towards the Mabinogion legend but was an "anti-novel".
"When you start writing as a hobby at 50, you can afford to experiment," he told the audience.
Katie Gramich, a member of the judging panel, said the three short listed novels were "about Wales but with nothing parochial about them".
Evans, who has lived on the Llyn peninsula for 40 years, said: "Wales has given me more context and confidence. For a writer it's a very welcoming environment."
Of her Growth Rings collection she added: "Almost every poem deals with a moment of discovery or resolution - it marks a moment of growth."
Perrin admitted climbing gave him a chance to study the characters of fellow climbers - and also offered a different perspective on the Welsh landscape.
Llwyd Owen's winning novel in Welsh is set in Cardiff
For the Welsh prize, Llwyd Owen's second novel "Fydd, Gobaith, Cariad", was selected over a novel by Gwen Pritchard Jones, and a biography of Saunders Lewis by Robin Chapman.
Described as a "powerful and profound" novel, its central character Alun Brady has led a sheltered life in a Cardiff suburb until he is thrown into bizarre new situations.
The longlists had been announced by Welsh literary body Academi on 2 March and included veteran poet Dannie Abse and Man Booker-nominated writer Sarah Waters.
The prize is administered by Academi, with funding from the Arts Council of Wales and the Welsh Assembly Government.
The two winners in 2006 were Robert Minhinnick for To Babel and Back and Rhys Evans for his biography Gwynfor: Rhag Pob Brad.