Ireland's Paul Dunne produced a stunning final round to hold off a thrilling challenge from Rory McIlroy and claim his first European Tour title in the British Masters.
Dunne, who sprang to prominence after sharing the 54-hole lead in the 2015 Open Championship while still an amateur, fired seven birdies and an eagle in a closing 61 to finish 20 under par.
And the 24-year-old sealed victory in style by chipping in on the 18th to finish three shots clear of McIlroy, whose 63 was the lowest score of an injury-plagued season which he will bring to an early, self-imposed end next week.
Ryder Cup vice-captain Robert Karlsson, who began the day with a one-shot lead, finished third on 16 under with Graeme Storm, David Lingmerth and Florian Fritsch on 14 under.
Dunne, who lost a play-off to Edoardo Molinari in the Hassan Trophy in April, enjoyed a remarkable stroke of luck when his approach to the 11th pitched into a sprinkler head on the edge of the green and bounced back to within five feet of the hole.
But the good fortune was well deserved after the 24-year-old played the first six holes in five under par to move into a lead he would never relinquish, with the victory - worth £500,000 - lifting him into the world's top 100 for the first time.
McIlroy was always playing catch-up despite a hat-trick of birdies from the sixth and his chance of a first win of the year looked to have gone when he missed good chances on the ninth and 10th and bogeyed the next.
However, the four-time major winner refused to throw in the towel and carded four birdies in five holes from the 12th, before coming within inches of driving the green on the short par-four 17th.
From a tricky lie on the edge of a greenside bunker, McIlroy chipped to four feet and holed for birdie to close within a single shot, but a lengthy birdie attempt on the last was never on line.
That left Dunne needing to par the final two holes for victory but he birdied the 17th and chipped in for another on the last, a fitting end to a week which saw record crowds of 60,180 in attendance.