American short story writer Claire Vaye Watkins has been named the 2013 winner of the £30,000 Dylan Thomas Prize for new writers.
Judges said she was an "exceptional" writer and described her collection Battleborn as "infectious".
The California-born 29-year-old was one of seven writers aged under 30 shortlisted for the prize.
The prize, based in Thomas's birthplace of Swansea, is one of the largest literary cash awards in the world.
"It has been such an honour and a treat to be part of this," Ms Watkins said. "I'm grateful for every single reader I have.
"It was not written for New York or London, it was written for people like you and Dylan, and anyone else that's been told their place doesn't matter."
Ms Watkins was presented with her prize at a ceremony at the city's National Waterfront Museum.
"Claire Vaye Watkins has some of Dylan Thomas's extraordinary skill in the short story form of giving you a perfect vision of a complete world and that's extraordinarily rare," said the chair of this year's judging panel, Hay Festival founder Peter Florence.
Singer and broadcaster Cerys Matthews, also on the judging panel, added: "Battleborn just bubbles. She is such a natural writer.
"The whole book is so infectious - it leaves you looking forward to what is coming next from this exceptional young author."
The collection of short stories in Battleborn examines some of the myths of the American west, from how a man responds to finding a cache of letters and pills on the roadside, to sisters unable to comfort each other following their mother's suicide.
"How exciting is it that in the year when Alice Munro is the greatest exponent of the modern short story by winning the Nobel Prize in Literature, that the Dylan Thomas Prize finds another truly remarkable short story writer in Claire Vaye Watkins?" said another judge, Telegraph columnist Allison Pearson.
"At aged just 29 years old, she is truly gifted."
Cultural historian Peter Stead, chair of the Dylan Thomas Prize, said this year's shortlist was the strongest it had ever had.
"We admired all the books and in the adjudication we discussed them all at length. There were several books in contention but our choice of Battleborn was unanimous," he said.
The judging panel considered three novels, two poetry collections, and two short story collections.
Thursday's prizewinner announcement follows a week of events involving all seven shortlisted writers, known as the DylanED programme.
It has seen them visit schools and universities across Wales to give readings and take part in creative writing workshops.
Those taking part included the one Welsh writer on the shortlist, Jemma King.
She was nominated for the prize for her collection of poems, The Shape of a Forest.