'The Lost Soul of Eamonn Magee' - Paul Gibson's book on the extraordinary life of the Belfast fighter - has been named joint-winner of the William Hill Sports Book of the Year award.
It is the first time the award has been shared during its 30-year history, with Tom Gregory's A Boy in the Water splitting the prize after a dead heat.
Gibson’s book chronicles the highs and lows Magee experienced inside and outside of the ring.
Donald McRae, a previous two-time winner of the award and Guardian sportswriter, said: "Eamonn Magee has lived a harrowing life. But it is a life that gains fresh meaning in this raw, riveting book.
"Magee thought he had run out of luck years ago but, this time, he got lucky again. In Paul Gibson he has found a writer who has the grit and the tenderness, the skill and the heart, to lay Magee's life bare on the page ... and uncover the humour and even the beauty of a dark story."
A Boy in the Water meanwhile follows the story of how Gregory, aged 11 years and 336 days, became officially the youngest person to swim the English channel in 1988.
The £30,000 cash prize will be split equally between the two books, with both authors receiving a £15,000 cheque, a free £1,000 William Hill bet, and a day at the races.