Andres Romero, the world number 837, fired a stunning seven-under-par final round of 65 to win his second European Tour title at the BMW International Open in Munich on Sunday.
The Argentinian, 36, went into the final day three strokes adrift of Richard Bland and world number five Sergio Garcia, but ended up winning by one shot from that pair and Belgian Thomas Detry.
Romero, who has struggled with form and fitness in recent years, belied his lowly ranking with a fantastic performance to claim his first title on either the European or PGA Tours since 2008, in his first appearance at a regular European Tour event for five years.
"The whole round was very good. I was focused all day," tournament invite Romero told the European Tour website.
"I didn't make any bogeys, that is a rare thing for my type of game. The last few holes I noticed I made seven birdies but the whole round was excellent."
For Garcia, it was a disappointing finish after being in contention all week, but the Masters champion looks in good form ahead of next month's British Open.
"I felt like I played well enough to win for sure," he said.
"Obviously a couple of missed putts here and there today and some really good putts that didn't want to go in.
"Any time you have a chance of winning, there's a lot of good things."
Detry made the first move, with five birdies on the front nine to briefly take the lead, but a bogey on the 10th put a halt to his charge, as the focus turned to the final group of Garcia and England's Bland.
The overnight leaders sprung into action around the turn, as Bland poured in three consecutive birdies to the Masters champion's two in three holes as the pair moved a stroke clear.
Romero catapulted himself into a tie for the lead though with six birdies in eight holes, before picking up another at the par-five 18th to set a clubhouse target of 17 under par.
Garcia and Bland carded late bogeys, meaning that they both needed an eagle on the 72nd hole to force a playoff.
Garcia narrowly failed to chip in with his third shot, before Bland's 15-foot eagle putt slid past the right edge to confirm Romero's unlikely victory.