Gregory Hughes was named the winner of the Booktrust Teenage Prize 2010 for his first literary effort, Unhooking The Moon.
He beat shortlisted authors such as Fast Show star-turned-young James Bond author Charlie Higson and Marcus Sedgwick, with judges hailing his "genuinely unique voice".
Mr Hughes was expelled from a Jesuit school in his native Liverpool as a teenager and spent time in a detention centre.
He went on to work as a removal man, window cleaner and dishwasher, before becoming a deep sea diver. It was while taking his GCSEs when in his 20s that he completed his first major piece of written work - an account of his time sleeping rough in New York's Times Square.
Unhooking The Moon follows two sibling orphans, Rat and Bob, on a perilous road trip to New York, and was written while Mr Hughes lived in a small room in Iceland.
Chair of judges Tony Bradman said: "All of us felt that Unhooking The Moon stood out from the beginning of our discussions. I have no doubt that this debut marks the beginning of a great career."
The author was awarded a 2,500 cheque at a ceremony in London.
Past prize winners include Neil Gaiman and Mark Haddon.