A brilliant back nine 31 saw Julien Quesne snatch the 70° Open d’Italia Lindt at Golf Club Torino and claim his second European Tour title.
The Frenchman began the day four shots off the lead and looked out of contention when he ran up a double-bogey six on the second, but birdied the fourth and sixth and then stormed home in 31.
The 33 year old picked up shots at the tenth, 11th and 15th before chipping in from short of the 17th green and holing from six feet for another birdie on the last to complete a closing 67.
That set the clubhouse target on 12 under par just moments before overnight leader Marcus Fraser, who was also 12 under, three-putted the 15th and dropped another shot on the par- three 16th after missing the green from the tee.
Fraser eventually signed for a 74 to finish joint eighth on nine under, leaving Ireland's David Higgins and England's Steve Webster to share second on 11 under.
Higgins, who had managed just one previous top-three finish in more than 200 European Tour events spanning 20 years, had birdied the 18th to match playing partner Webster's closing 68, the 2005 champion having threatened to claim the title again when he holed from 60 feet across the 17th green.
Quesne, whose previous win came in the Open de Andalucía last year, said: "I am very proud of this back nine. My attitude was very good this week and I think this is the key. To enjoy a second win on The European Tour is like a dream for me.
"After my double bogey I just kept calm. I was thinking the winner would be 15 under and I was only five under. I thought 'just keep working and we will see what happens'.
“Then, when I got to the 16th green I looked up at the leaderboard and realised that I was just two shots off the lead and I knew that I still had a chance. I made a great putt there from five metres to save par and to make two birdies to finish was very special. When I made the birdie on 17 I thought that if I could get to 12 under then I would have the chance at least to get into a play-off. You never know in golf, so I am proud that I kept the attitude the way I did because I always knew that I was never out of the tournament.
"I am surprised to be here. The flags were very difficult all week so it was very difficult to make birdies and easy to make some bogeys.
“It was also really special to have my family with me – they make me stronger when they are with me and it is an amazing feeling to be able to celebrate here with them.
“I have had a great season this year – it has been a very consistent season with six top tens before this week and now it has become an amazing season. I can now play so many of the biggest events at the end of the year and try to finish as high as I can on The Race to Dubai.”
The victory lifts Quesne to 41st on The Race to Dubai - the top 60 qualify for the season-ending DP World Tour Championship in Dubai - while Higgins climbs from 163rd to 111th.
The top 110 after the Perth International in mid-October will keep their playing privileges for 2014, meaning if Higgins can advance further he will avoid a 14th visit to Qualifying School.
"I was very lucky on the last, I hit an awful tee shot but got a good lie in the fairway bunker," Higgins said. "You still have to play the shot and I did and got the putt so I was delighted.
"I thought 'How many chances am I going to get of maybe tying for the lead?' so I said 'come on, you've got to at least give it a good run and be positive with it', and it went right in the middle.
"I had good practice rounds at the start of the week and I am proud of myself for taking that into the competition itself. I haven't had a finish like this in 17 years so I am delighted. I can do it and I just have to do it more often I guess."
Webster has been struggling with a wrist injury all season but said: "It's the first time I have played for four months without pulling out of a shot or feeling 70 per cent so hopefully this is a big turning point for me now."
Club member Francesco Molinari briefly threatened a fairytale victory when he recovered from two early bogeys by holing a bunker shot on the eighth and making a birdie on the ninth, but the Ryder Cup star stumbled home in 39 to finish seven under.