Hilary Mantel has done the double - winning the Costa Book Award for her Man Booker Prize-winning Bring Up The Bodies.
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, who won the Man Booker last year, said she was "not going to apologise" for winning this year's Costa.
She said: "I'm not sorry, I'm happy and I shall make it my business to try to write more books that will be worth more prizes".
Speaking to reporters afterwards, she said: "I was writing for many years and I was not among the prizes at all or I was the perpetual runner-up.
"Things have changed in a big way, I feel my luck has changed but of course that's not true. What's changed is what I'm working on, possibly a project that's played to my strengths and a project that came along just when I was ready for it."
She admitted the success of the book, which is being adapted for television productions and stage plays by the Royal Shakespeare Company, had become "a phenomenon".
She said: "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."
Mantel admitted she had "a secret wish to write a stage play" but said she would leave it to the professionals and enjoy her "ringside seat" watching the adapted versions develop.
But she added there would "come a time" when she had to get back to writing the final part of the trilogy, saying: "Also, I'm excited about it, I want to know what happens, I want to know what I'll say."