Corban Wilkins was announced as the recipient of the award on Saturday (November 3) night, reports the Forbidden Planet International blog.
He received the prize for his four-page tale of "friendship, obsession and alien landings", But I Can't.
Steve Tillotson was named runner-up for his story I, Yeti.
Wilkins is currently seeking a publisher for his graphic novel Breaker's End, which follows the adventures of a couple living in the woods.
The previous five years' winners are part of an exhibition at London's Foyles bookshop until November 16.