Paul Peterson held off the challenge of defending champion Thomas Pieters to claim a maiden European Tour victory at the Czech Masters.
Peterson mixed seven birdies with two blemishes on his way to a five-under 67 at Albatross Golf Resort, picking up a shot at the last to finish one-stroke clear of the Belgian.
In a topsy-turvy final round, the pair traded places several times at the top of the leaderboard and were all-square until Peterson birdied the 16th and 18th.
A runner-up finish for Pieters ends his hopes of automatically qualifying for Europe’s Ryder Cup side this autumn, as Matt Fitzpatrick secured his spot for Hazeltine by ending the tournament in fifth place.
Beginning the day two strokes clear, Pieters bogeyed the par-five first as Peterson made birdie to move in to a share for the lead.
Pieters regained his two-shot cushion by picking up a shot at the next, but saw his advantage cut to one when Peterson bounced back from a blemish at the second to card a birdie-two at the third.
Peterson pulled back level with a gain at the sixth, before rolling in a six-footer at the ninth to reach the back nine one ahead.
The pair were tied again when Peterson failed to get up-and-down from a greenside bunker at the 11th, with the duo extending their advantage over the field with gains at the par-five 12th.
A run of pars for the leading pair came to an end when Peterson’s tee shot at the 16th left a close-range birdie, before the world No 398 sealed the title by draining a 20-footer at the last.
“This is the best feeling in the world,” Peterson told Sky Sports. “This (a European Tour win) was always a goal this year, so to be able to accomplish it means so much.”
First round leader Ryan Evans posted a bogey-free 68 to end the week tied-third with David Howell, as Matt Fitzpatrick carded a third 69 of the week to finish five strokes adrift.
English trio Graeme Storm, Robert Rock and Gary Boyd joined Robert Karlsson in a tie for seventh, while Ryder Cup hopeful Lee Westwood birdied two of his final three holes to close a level-par 72.