Hilary Mantel won Britain's Costa Book Award for her novel "Bring Up The Bodies", which has now done the double having claimed the Booker Prize.
The judges described the book, the second part of a planned trilogy about king Henry VIII's adviser Thomas Cromwell, as "head and shoulders" above the other contenders.
Mantel, 60, scooped the £30,000 ($47,000, 35,000 euro) prize, while the other writers on the shortlist, made up from the other four category winners, received £5,000 each.
"I'm happy and I shall make it my business to try to write more books that will be worth more prizes," she said on Tuesday.
"Sometimes it feels like it's getting away from me, yet at the same time I'm still contained within it because I have the third book to write.
"I'm excited about it. I want to know what happens, I want to know what I'll say."
Mantel made literary history in October 2012 by becoming the first woman and the first British author to be a two-time winner of the Booker Prize for fiction, one of the highest profile awards in English-language literature.
The Costa Book Award, formerly the Whitbread Literary Awards, was established in 1971 to celebrate contemporary British and Irish writing. A panel of writers, actors and broadcasters choose the most enjoyable books from the past year.
Broadcaster Jenni Murray, who chaired the nine-strong judging panel, said they had made a unanimous decision.
"This is a very difficult prize to judge because there are five categories and they are so different: poetry, children's, biography, first novel and novel," she said.
"One book simply stood head and shoulders, more than head and shoulders -- on stilts -- above the rest.
"We couldn't allow the number of times it has already been lauded to affect our decision; it was quite simply the best book."