Francesco Molinari clinched the Race to Dubai title after Tommy Fleetwood failed to win the season-ending DP World Tour Championship, where England's Danny Willett earned his first title in 2-1/2 years on Sunday.
Molinari has enjoyed a remarkable season, winning his maiden major championship at the British Open along with his first Rolex Series title at the BMW PGA Championship.
Englishman Fleetwood, who needed to win at the Jumeirah Golf Estates to overtake Molinari on the European Tour's money list, finished with a final-round four-under-par 68 to end 10-under overall, eight shots behind eventual winner Willett.
"It's incredible," Molinari said. "Now I'm going to have time to sit down and relax and really think back about the last few months.
"This morning on the first tee the announcement is the winner of The Open Championship, Race to Dubai leader, it doesn't sound real at the moment.
"It's more than I ever dreamed of achieving. I've seen guys that I think are better players than me not winning Majors and not winning Order of Merits or Race to Dubais. To achieve those things in one single season is just incredible."
Molinari was also part of Team Europe's Ryder Cup victory over the U.S. at Le Golf National in September, becoming the first European to win five points out of five.
Four of those points were won in a pairing with team mate Fleetwood.
"It's tough in a way because it would have been probably easier in a way to play against anyone else but him (Fleetwood)," Molinari added.
"I know how talented he is and I really thought at some point he was going to win it and put me in a tough spot.
"He's obviously a great guy and a super talented player and I'm sure being younger than me, he's going to win a few more Race to Dubais."
Willett produced a late birdie spree to return to the winners' circle for the first time since his memorable U.S. Masters triumph in 2016.
The 31-year-old looked to have missed his chance when he began the back nine with two bogeys in three holes.
Yet birdies at 14, 15 and 17 ensured he signed for a final round 68, finishing two shots ahead of playing partner Patrick Reed and compatriot Matt Wallace.
Willett missed five of his first seven cuts this season but a tied-eighth finish at the Italian Open sparked his campaign to life, before he claimed his sixth European Tour title on the Earth Course.
"You never quite know when a win is around the corner and with all the things that have happened, I was never quite sure if it was going to happen again," he said.
"To happen here at the end of year, we've battled long and hard through this season to come out at the end, regardless of what happened today, a better person and a better athlete. It's a special place."