Despite gusty winds and cool temperatures on the Northeast coast of Scotland, McIlroy rattled off eight birdies and a bogey Thursday morning at Royal Aberdeen to take the early, first-round lead at the Aberdeen Asset Management Scottish Open.
The annual European Tour event is viewed as an excellent warm-up event for next week's Open Championship, as in recent years it has been played on a true links course.
For McIlroy, it was the fourth time this year he opened a tournament with a round of at least 7 under. Three times he has shot 63. His 64 here set a Royal Aberdeen course record.
"Anytime you can start a tournament with a score like that, you are very pleased, and it's obviously something to build on for the next three days,'' said Mcllroy, who is coming off a two-week break. "But more importantly, I was just really pleased with how I controlled my game. I controlled my ball flight. Some of the shots that I was practicing over the last 10 days ... to go out today and be able to trust it in a tournament round was great.
"So regardless of the score, just the way I played today was the most pleasing thing.''
McIlroy was a shot ahead of Argentina's Ricardo Gonzalez and Sweden's Kristoffer Broberg. England's Luke Donald was in a group that shot 67.
Phil Mickelson, in his first competitive round since a disappointing finish at the U.S. Open last month, shot a 3-under-par 68 that saw his only bogey at the last hole. Mickelson, the defending champion, won this event a year ago at Castle Stuart, a relatively new links layout, before going on to win the Open at Muirfield.
"I was pleased with the way I putted,'' said Mickelson, who has struggled on the greens for most of the year and has failed to post a top-10 finish on the PGA Tour. "Even though I missed that one at the last hole [for par], I putted much better. It's a good start.''
McIlroy is used to starting fast. He began the Dubai Desert Classic, the Honda Classic and the Memorial with rounds of 63, but he didn't go on to win any of those tournaments.
He played in the final group in Dubai but slumped in the final round, lost in a playoff at the Honda, and followed his opening 63 at Muirfield Village with a 78 that left him scrambling on the weekend.
That tournament was part of a four-event stretch on the PGA Tour in which he had a Friday nine-hole score of 40 or worse.
"I think it's more mental than anything else, to be honest. Trying to keep yourself in the lead or keep yourself up there,'' McIlroy said. "But I don't think it's anything more than that.''
Although McIlroy holds the course record at two other famous links -- a 61 at Royal Portrush in Northern Ireland when he was 17 and a 63 at the Old Course at St. Andrews during the first round of the 2010 Open Championship -- he has never been particularly fond of this style of golf.
But he's worked hard to hit the kind of shots that bring success in these conditions.
And there were a few interesting ones Thursday, including a drive of more than 400 yards to the 436-yard, par-4 13th. McIlroy said he had never driven a par-4 of that length, his tee shot aided by a strong wind at his back and the bounces of a hard links surface.
"It was nice,'' McIlroy said. "Wind assisted and downhill and firm conditions, but it was a good drive. I was confident with it because I knocked it on the green yesterday in the pro-am. So I was pretty sure of what line to take, and just stepped up and hit a good one.''
The drive was so good the players in the preceding group, including Ian Poulter, were still putting as the ball trickled onto the surface.
"I told Poulter it was a 3-wood,'' McIlroy quipped.