After a fog delay of nearly three hours, the 31-year-old wasted no time in showing his intention to begin the year on a winning note in the $8 million Abu Dhabi HSBC Championship.
McIlroy, who has finished second three times in this event and been third on three other occasions, carded eight birdies - four in each half of the card - to lead by a shot from Englishman Tyrrell Hatton when play was suspended for the day.
The Northern Irishman had shot 65 on three previous occasions at this venue and was delighted to finally go one better alongside world No 3 Justin Thomas and defending champion Lee Westwood in the morning wave’s marquee group.
“Yeah, it feels good,” McIlroy, who recorded his breakthrough win on the European Tour in the Dubai Desert Classic in 2009 before landing the title again 2015, as well as a brace of DP World Tour Championships in Dubai, told Sky Sports Golf after his round. “I actually thought that to myself after I turned in four-under.
“I knew 65 is the best I've shot here and I've shot it a few times, so I thought let's try to go one better on the next nine and I was able to do that. It was obviously a lovely way to start the year.”
In his first competitive round since tying for fifth in The Masters in November, the four-time major winner looked sharp in all aspects of his game.
His driving was majestic, his yardage control was spot on and, perhaps most pleasing of all for him, he enjoyed a profitable day on the greens.
On the couple of occasions he was in danger of dropping a shot - at the fourth and seventh, both par-3s - his short game was also up to the task.
“A lot of it was very good,” he added. “I felt like I drove the ball well for the most part. Distance control was really good. Hit a lot of nice iron shots.
“But, honestly, it was probably the best I've putted these greens in Abu Dhabi probably in my whole career.
“I've always struggled to read them here, but I sort of got my eye in early and I holed some really good ones today.”
Last year, when he decided to open up on the PGA Tour rather than out in the Middle East on the European Tour, McIlroy recorded five straight top-five finishes before golf was hit by its Covid-19 lockdown
After the US circuit restarted, he then took nine events to chalk up a top-10 finish, admitting it had been awkward at first for him to adjust to playing in events without any fans in attendance.
“One of the first breakthroughs I made (last year after the Covid-19 lockdown) was the second PGA Tour Play-Off event, the BMW Championship at Olympia Fields,” said McIlroy. “I played well there and felt like I sort of found something.
“Next week, our daughter was born and I went to the Tour Championship and ended up playing pretty well.
“Played pretty well at the US Open with a couple of not-so-great rounds, and then played okay at the Masters, just apart from a bad nine holes.
“It was getting better as the year went on, and honestly it was sort of disappointing that it finished when it did because I felt like I was getting right back into it.
“I didn't really take much time off after Augusta. I sat at home for maybe three or four days and was like I just need to get out there and sort of keep this going.
“Played quite a bit over the Christmas break and practiced quite a bit. Felt maybe as sharp as I've ever done coming into the start of the season. It's paid off early.”
Hatton, who won on both the European Tour and PGA Tour last year, sparked his pleasing day’s work by hitting a 3-wood to around five feet at the tenth before almost making an albatross-2 at the 18th courtesy of another brilliant blow with a fairway wood from just off the fairway.
“Obviously two good shots,” he said of those efforts. “It's not often you're hitting 3-wood to five feet and a nice one to start the day.”
Continuing to work well with his Scottish caddie Mick Donaghy, the 29-year-old added birdies at the second, fourth and ninth as he matched McIlroy in opening with a bogey-free round. “I'm really happy with that,” added Hatton.
Westwood, the European No 1, opened with a 69, the same as two-time Omega Dubai Desert Classic winner Stephen Gallacher, but Thomas struggled to a 73 in his first event since being dropped by clothing company Ralph Lauren over a homophobic slur.
“It was solid stuff and I’m pleased with it,” said Westwood of his effort. “I hit the ball quite nicely and rolled the ball well on the greens.”
On being in the same group as McIlroy and Thomas, the 47-year-old added with a smile: “Played behind them. Wasn't playing with them most of the day. What a shock that is.
“I kept hitting it 215 and 220 and that's not long enough for these lads. These lads are getting out 240, 250. They are fun to watch. Not only do they hit it a long way but they hit it a long way straight. There should be an advantage to that.
Paraguay’s Fabrizio Zanotti carded a 66, one better than former Scottish Open champion Rafa Cabrera Bello and Romain Langasque, who won the 2015 Amateur Championship at Carnoustie.
Play was suspended due to darkness at just before 6pm UAE time, with former US Open champion Justin Rose sitting on three-under with eight holes to play.