Collin Morikawa became the first American to win the Race to Dubai after clinching the DP World Tour Championship title on Sunday.

The 24-year-old entered this week's season finale knowing there were five challengers who could pip him to the European number one crown, although he teed off on Sunday with a three-shot advantage over his nearest rivals.

Morikawa showed few nerves as he produced his best round of the tournament, carding a 66 to finish three strokes ahead of Alexander Bjork and Matt Fitzpatrick at 17 under par.

It capped a memorable 2021 for Morikawa, who has won three titles this year, including the Open Championship in July, having only made his professional debut in August 2019.

"It's special, it's an honour, really, to be the first American to do that on the European Tour to put my name against many, many great Hall of Famers, it's special," he said.

"Two years ago, it wasn't in my thoughts. It was, 'yeah, let's go play around the world' but we didn't know what the cards were going to be dealt.

"To have this chance and finally close it out, and not just closing it out with a top 10 or something, but to actually win the DP World Tour Championship, which concluded with the Race to Dubai, not a better way to finish – what a great way to finish.

"To close out the season-long race, the Race to Dubai, it means everything. Obviously, I won some big events and that obviously helped catapult me up to the top."

Rory McIlroy, who led after the first day at Jumeirah Golf Estates, finished in a tie for sixth with Dean Burmester and Ian Poulter after a final round of 74 left him at 12 under.

The best performance of the day belonged to Bernd Wiesberger, who carded a brilliant 63 to finish on two over after only managing 76, 76 and 75 in the first three rounds.

Rory McIlroy leads the season-ending DP World Tour Championship after the opening round, but Race to Dubai frontrunner Collin Morikawa was Thursday's big winner.

A seven-under 65 gave McIlroy a two-stroke advantage at the top of the leaderboard at Jumeirah Golf Estates, with Tapio Pulkkanen, Joachim B. Hansen and Christiaan Bezuidenhout in a three-way tie behind him.

McIlroy, whose 14th and most recent European Tour win came at the WGC-HSBC Champions in 2019, made a flying birdie-eagle start and only dropped a single shot all day at the ninth.

After turning in 31, the Northern Irishman protected his day-one advantage over a steady back nine.

McIlroy, who beat Morikawa at the CJ Cup last month, believes he has "got [his] golf game back" since contributing only a single point to Europe's Ryder Cup defeat.

"I'm just excited for the road ahead, because I feel like I'm on the right path," he said.

But the main focus this week is on the Race to Dubai, in which McIlroy is 20th and out of the running.

First-placed Morikawa has competition chiefly from fellow American Billy Horschel this week following Jon Rahm's withdrawal, although four other players could also yet scoop the seasonal title with 2,000 points on the line in Dubai.

Of the six contenders, Morikawa is best placed heading into Friday after his four-under 68 secured a share of fifth.

Crucially, Horschel endured a difficult start as three bogeys across four holes on the back nine set him back and he carded a two-over 74 – a hugely damaging deficit given his need to outperform Morikawa.

Rounds of 70 for Tyrrell Hatton, Matt Fitzpatrick and Paul Casey kept the English trio in the mix, although each need to win and see Morikawa struggle. Min Woo Lee, the sixth man in contention, has work to do from even par.