Rasmus Hojgaard became a three-time European Tour winner at the age of 20 after producing a closing bogey-free 63 to come through the field and claim a one-shot victory at the Omega European Masters.
The 18th hole at Crans-sur-Sierre Golf Club proved crucial on Sunday, with Hojgaard holing his nine-foot birdie putt there to get to 13-under-par.
He walked off the course trailing Bernd Wiesberger by one shot, but that all changed as the Austrian found the water at the last hole to surrender a double-bogey and slip to 12-under-par.
Hojgaard's nervous wait continued as the final three groups finished off their rounds, but with none of the remaining players able to match his 72-hole total.
He was crowned King of the Mountains, becoming the third-youngest player to get to three wins on the European Tour, following Matteo Manassero and Seve Ballesteros, who was a three-time winner of the event.
Wiesberger finished alone in second, one shot behind Hojgaard with Henrik Stenson another shot behind on 11-under-par. English pair Matthew Jordan and Ross McGowan joined American Sean Crocker in a tie for fourth at 10-under-par.
"At the moment it's a bit surreal to be fair. I didn't expect to be in this position but it's amazing," said Hojgaard.
"I knew I had to make a birdie (at the 18th hole) to have a chance to maybe get in the play-off, so we were just trying to set up a chance. I made a birdie and then we had a bit of a strange ending. It was crazy.
"That's by far the most nervous I've been the whole day (over the putt at the 18th hole). But it's so nice to have the crowds back to cheer you on. That was a great moment."