Marcel Siem held off a stunning final round charge from Francesco Molinari to claim his second European Tour title at the Alstom Open de France.
Six behind overnight, Molinari double bogeyed the first but responded with nine birdies in a stunning 64 - the best round of the week at Le Golf National.
However, the Italian’s magnificent display - underpinned by fabulous iron play in blustery conditions - ultimately proved in vain as Siem held his nerve down the stretch en route to a 67 that saw him finish one clear on eight under.
Siem, whose only previous win came at the 2004 dunhill championship, saved par at the first despite finding water from the tee and was able to avoid any dropped shots up until the 18th.
He turned in 33 and added further birdies at the 14th and 15th to move ahead of Molinari, whose back nine 29 will live long in the memory of those who witnessed it.
A closing bogey mattered little to Siem, who gains a place in The 141st Open Championship and becomes the third German to have triumphed at this event after Bernhard Langer and Martin Kaymer.
“I'm so happy. This means a lot to me,” said Siem upon receiving the trophy and a cheque for €525,000.
"First, after eight years it doesn't matter what kind of tournament you won; it's huge, because you've got the confidence again. Every time I've played consistent golf this year, and there were so many times up there, I couldn't make it. Stupid things happened the whole time.
“It means so much to me to win after that long stretch. It's all about winning in the end and it puts so much pressure every time you don't win and people start talking, you will never win again and stuff like that, so it's very important for me.
“I love this golf course. I always loved it and I love it even more or even better now. I'm super happy.”
Siem admitted he had struggled to keep his emotions in check as he entered the notoriously difficult final four holes.
“I was very nervous, I have to say, after 14 when I made the up and down out of the trap,” he added.
“The last stretch is one of the toughest stretches we have on Tour. In Cologne (at last month’s BMW International Open), I hit it in the water on seven, (when in the) last round I was leading.
“But I made great golf shots. I hit it close on 15, made a good shot on 16 that wouldn't drop and even 17, hit the flag. I stayed very calm. That was very nice.
“Now I've got the win it’s going to make me relax a lot more now.”
Despite being pipped to the title this week, Molinari was able to reflect on a staggering final round performance.
“It's been just an unbelievable day really,” he said.
“I had a really bad start, but two years ago when I finished second here, I doubled the first on the last day.
“From then on, it was just great golf. I had a couple of good breaks and finally a lot of putts going in the hole.
“I was in the moment, in the zone and I wasn't really counting the birdies. The game has been feeling well all week and everything was coming out perfect.”
Siem’s playing partner Henrik Stenson impressed on the inward nine, but, after making four birdies to reach seven under, the Swede hit trouble at the last and finished with a triple bogey.
Home favourite Raphaël Jacquelin therefore claimed third spot on six under, with the English trio of David Lynn, Ian Poulter and David Howell a shot further back in fourth.
Howell began the day as the joint leader with Denmark’s Anders Hansen, who went round in 75 to end the week on two under.
World Number Three Lee Westwood climbed 18 places to 40th with a closing 70.
That came a day after it looked as if he might be pulling out with knee and groin trouble after he slipped walking to the first tee.
"The leg is fine - it wasn’t a problem today," Westwood said, after completing his final round before The Open at Royal Lytham and St Annes starting on Thursday week.