David Lilly denied Jimmy White a third consecutive world title after winning 5-3 in the final in Sheffield.
The 45-year-old from Washington was playing in the later stages of the event for the first time.
He made his competitive debut at the Crucible after passing his initial Q-School qualification in Reading earlier this year.
Lilly took a 3-0 lead and although White tied the score 3-3, Lilly pulled out again for the win.
“I’m a bit speechless,” he said, “I didn’t think I’d get those feelings.”
“Jimmy is my hero – he’s everyone’s hero. I really don’t know what to say; I’m so happy.”
Lilly eliminated Philip Williams, Ken Doherty and Patrick Wallace on his way to the final.