Hunter, who began the year's first world ranking tournament as an 80- 1 outsider, beat the hot favourite John Higgins 9-5.
"It's unbelievable but my dad always said I would have my day," said the 19-year-old from Leeds, who had already beaten Steve Davis, Nigel Bond, Alan McManus and Peter Ebdon in the competition.
"Never in my wildest dreams did I think this would happen so soon in my career."
Hunter, taking a major final debut in his stride, had breaks of 127 and 116 to share the opening four frames. The turning point came in the 11th frame when Higgins missed a straight-forward red to the middle pocket and Hunter, assisted by a 51 break, edged ahead for the first time in the contest at 6-5.
Higgins squandered what proved to be his last chance in the 12th and, from 7-5, Hunter finished in style.