Thongchai Jaidee left Rory McIlroy and a host of other big names trailing in his wake as he secured an emphatic victory at the Open de France.
Veteran Thai Jaidee, now an eight-time winner on the European Tour, began Sunday's final round holding a two-stroke advantage over McIlroy and Jeunghun Wang, with defending champion Bernd Wiesberger, Martin Kaymer and Andy Sullivan among others in contention.
However, those hoping for a dramatic finale at Le Golf National - the venue for the 2018 Ryder Cup - were left disappointed as Jaidee produced a nerveless display to surge clear of the field.
A closing 68, featuring two birdies on each nine and a solitary bogey at 18 with the title already in the bag, ensured the 46-year-old triumphed by four shots at 11 under.
Asked at the post-tournament presentation if the win represented the biggest of his career, Jaidee said: "Absolutely. I played great this week. No complaints at all.
"I tried to play my own game, hit a lot of fairways and a lot of greens.
"My game is getting better. I played well last week, the only thing was putting. I knew this week I was putting well."
Francesco Molinari finished with a 66 to vault into second place, while McIlroy had to settle for third at six under following a 71 that contained 16 pars and Rafael Cabrera-Bello (67) was a shot further back.
Kaymer had been Jaidee's nearest challenger after picking up four shots in 10 holes, but the German slipped back into a tie for fifth alongside Sullivan and Brandon Stone after bogeying the 12th, 14th and 15th.
As the highest-placed finisher not already qualified for The Open, Stone booked a place in this month's major at Royal Troon, together with Alex Noren, Callum Shinkwin and Richard Sterne.
Wiesberger, slumped to a 75, leaving him 10 off the pace, while Wang fared even worse, shooting 78 to end the week over par.