November 22nd 2015, Dubai, United Arab Emirates: Rory McIlroy survived a late scare and finished his frustrating season on a high, winning both the DP World Tour Championship and the Race to Dubai crown on Sunday.

McIlroy got the better of overnight leader Andy Sullivan over the back nine to clinch the European Tour's season-ending tournament.

The third-ranked Northern Irishman shot 6-under 66 with eight birdies to finish at 21-under 267, one stroke ahead of Sullivan (68).

England's Danny Willett, who started the tournament 1,613 points behind McIlroy in the Race to Dubai and needed to beat him to become the European No. 1 for the first time in his career, finished tied for fourth at 13-under 275 after shooting 70.

South Africa's Branden Grace shot 5-under 67 in the final round to finish third at 273.

McIlroy had an anxious moment late in the day when his tee shot on the par-3 17th found the water and threatened to nullify his advantage at that stage.

But the 26-year-old McIlroy made a brilliant 40-foot putt to limit the damage to a bogey, which gave him a one-shot lead going to the 18th where he and Sullivan made par.

"In hindsight, I probably should have gone with a different club and a different shot," McIlroy said of his problems at the 17th. "It's definitely probably the longest putt I've ever made for a bogey. I don't think there's been one that's come at a better time. So, yeah, definitely the best bogey of my career."

McIlroy also won the Race to Dubai title as the European Tour's No. 1 player for the year, the third time he has secured the honor after winning in 2012 and 2014.

"To be European No. 1 for the third time in four years, that was a goal of mine at the start of the year. It was a goal of mine in the middle of the year and it was definitely a goal coming into these last few weeks," he said.

McIlroy's closest rival for the Race to Dubai was Willett, who made early birdies to climb to third place on the leaderboard, but both McIlroy and Sullivan had enough birdies of their own to stay comfortably clear. Willett needed to finish ahead of McIlroy in the tournament.

Sullivan had two birdies in the first two holes, and four in the first six. McIlroy bogeyed the fourth and trailed Sullivan by three shots at one stage, despite birdies on Nos. 5, 6 and 7.

But the birdies stopped for Sullivan as he started spraying his tee shots, and McIlroy edged ahead with two crucial birdies on the 14th and 15th holes.