Matthew Fitzpatrick beat Lucas Bjerregaard in a play-off to become the first man in 40 years to successfully defend the title at the Omega European Masters.
The Englishman started the day four shots ahead of Bjerregaard but the Dane carded a brilliant 63 to set the target at 17 under and Fitzpatrick had to birdie the last to take it to extra holes.
The 24 year old then put his approach to 12 feet on the first trip back up the 18th and another birdie saw him become the first player since the late, great Seve Ballesteros to go back-to-back at Crans-sur-Sierre Golf Club.
The final day had developed into an enthralling three-way battle between Fitzpatrick, Bjerregaard and Mike Lorenzo-Vera, with the Frenchman right in it until he bogeyed the last after finding the water.
Lorenzo-Vera finished at 15 under, three shots clear of Spaniard Nacho Elvira and four ahead of England's Daniel Brooks.
Fitzpatrick needed extra holes to beat Scott Hend in the mountains last season and became just the third player this term to mount a successful defence after Tommy Fleetwood and Brooks Koepka.
At 24 years and eight days old, he also becomes the youngest Englishman to get to five European Tour victories, having won in every season since coming through the Qualifying School in 2014.
“This is what I wanted to achieve this season - another win,” he said. “To get it here again is so special and to get my fifth is amazing. I love this place.
“Of all my wins I'd say that was definitely the most difficult. I didn't have my A game today, despite loving this place I just didn't play my best today. I managed to grind it out, made some crucial birdies coming in and I'm delighted. This is one of my best.
“The up-and-down on seven was key. After just making bogey on six, which is kind of my favourite hole, making birdie there got me back on track and within touching distance.”
Of all my wins I'd say that was definitely the most difficult. To get it here again is so special and to get my fifth is amazing - Matthew Fitzpatrick
Lorenzo-Vera birdied the first after a stunning approach to tap-in range and when Fitzpatrick flew over the back of third and could not get up and down from out of the trees, the lead was shared.
Bjerregaard had holed a 35-footer on the first and a smart pitch into the fifth and lovely approach into the next meant there was a three-way tie.
The 27 year old led alone when he drove the green at the par four seventh and got down in two, with Lorenzo-Vera dropping a shot on the fourth but picking it straight back up on the next.
A remarkable flop shot saw Lorenzo-Vera save par on the next but Fitzpatrick three-putted from the fringe and after starting the day two ahead, he was two off the lead.
Lorenzo-Vera drove the green and Fitzpatrick got up and down from the sand on the seventh for a pair of birdies but Bjerregaard made the most of the par five ninth to edge back ahead.
An incredible bunker shot saw Lorenzo-Vera birdie the same hole - with Fitzpatrick following suit after laying up - and the 33 year old holed a 15-footer on the tenth to lead on his own.
An 18-footer on the 13th briefly had him in a two-shot lead but Bjerregaard got on the green in two at the par five 14th and 15th, taking advantage on both occasions to get back into a share.
Lorenzo-Vera's second into the 14th flew into the bushes over the back of the green and after a penalty-drop and a three-putt, Bjerregaard suddenly led by two.
Fitzpatrick then got up and down from the front on the 15th green with Lorenzo-Vera doing the same from the sand as Bjerregaard set the target with three closing pars.
Lorenzo-Vera found the water with his approach to the last to end his hopes of victory but Fitzpatrick put his second to six feet and set up that big finish.
For Portugal Masters champion Bjerregaard, the result is a third consecutive top ten, while Lorenzo-Vera has three top tens this seasons as he looks for a maiden victory.
Elvira made a hat-trick of birdies from the 13th in his 66, while a double-bogey on the 17th took some of the gloss off Brooks' 69.
Japan's Hideto Tanihara and Chinese Wu Ashun were at ten under, a shot clear of South African pair Darren Fichardt and Charl Schwartzel, American Doug Ghim and Thai Phachara Khongwatmai.
Frenchman Adrien Saddier made the 32nd hole-in-one of the season and second of the week when he holed a seven iron from 192 yards on the 13th.