Rory McIlroy tried out his new swing for the first time competitively while shooting a 5-under 67 in the first round of the Abu Dhabi Championship on Thursday.
It left the No. 3-ranked McIlroy five shots off the lead held by Ryder Cup teammate Tommy Fleetwood in the first event of the European tour playoffs.
Seeking a victory that would clinch a sixth yearlong Race to Dubai title, McIlroy returned to competitive action after a month away -- most of which he spent shut away in a studio hitting balls against a screen in search of a more robust swing that can hold up in pressure-filled moments.
McIlroy didn't make too many mistakes in his first round, save for pushing his tee shot on the par-3 17th and failing to get up and down for par. That was his only bogey, while he made six birdies, including a tap-in at the last.
"It felt OK," McIlroy said, looking rather unimpressed. "I've gotten comfortable doing this little rehearsal before I take the club back. It felt fine. I probably wasn't as imaginative out there. I was hitting very straight shots.
"I hit a couple where I didn't see the picture of what I was trying to do with the ball flight because I was thinking a little too much about what I was doing with the swing."
McIlroy said the lack of wind and the generous size of the fairways at Yas Links made his task easier and allowed him to focus on his modified swing.
"I am quite fortunate that it's a nice week to come back," he said.
Fleetwood, the next-highest-ranked player in the reduced 70-man field at No. 10, was more in the zone, making eight birdies to go with an eagle at the par-5 second hole in a bogey-free round of 10-under 62 that tied the course record. The Englishman took the solo lead for the first time by rolling in a birdie putt from 10 feet at No. 18.
"Putted amazing," Fleetwood said. "Felt like I read the greens so well. Beautiful pace control and hit a lot of good putts and started holing them."
Fleetwood was a stroke clear of Thorbjorn Olesen of Denmark and Johannes Veerman of the United States, with LIV Golf's Tyrrell Hatton in a share of fourth place after shooting 64 with Laurie Canter, Paul Waring and Francesco Laporta.
McIlroy, who was in a tie for 18th, has a huge lead in the Race to Dubai standings and can win what was formerly the Order of Merit title with an event to spare with a victory in Abu Dhabi. That would take some suspense out of the season-ending World Tour Championship in Dubai next week.
He has finished a season as the European No. 1 five times and can tie the late Seve Ballesteros with a sixth. Colin Montgomerie has a record eight.
The Associated Press and Field Level Media contributed to this report.