Seven years have gone by since Rory McIlroy, as an 18-year-old amateur, turned up at Carnoustie and announced himself to the sporting world by shooting the only bogey-free round of the first day of the 2007 Open Championship.

A lot of water has flowed under those daft wee Barry Burn bridges since then. A lot of money has flowed through McIlroy's bank accounts as well, and a lot of headlines have been written about his life, loves, toils and travails. But, in one sense, nothing has changed.

Yesterday, just before 9.30am, McIlroy stepped up to the first tee at Hoylake and rattled off a safe par at the Merseyside course's 458-yard opening hole. Just over four-and-a-half hours later, he handed in a card unsullied by a single bogey. In stark contrast to his striking blue outfit, McIlroy's numbers were all red.

Much was being made of the fact that the sun was shining, the fairways were running, the greens were receptive and such wind as could be felt was what the old golf scribes used to call the merest of zephyrs. All true, but all the morning starters faced the same conditions, and Thomas Bjorn was the only one who could match McIlroy's flawless achievement.

Inconveniently, the Dane could not match McIlroy's scoring. Bjorn rattled off a couple of birdies, the Northern Irishman raised the bar with six of the things - and, with a little more luck, could easily have claimed three more.

It was a sublime performance. My last steps at the 2013 Open at Muirfield were in the wake of Phil Mickelson, the eventual winner, whose closing six holes were as fine an exhibition of golf as I've ever seen. My first at Hoylake this year were as part of McIlroy's travelling gallery. Maybe I should take in a few other players just to remind myself that not everyone is this good.

Actually, Jordan Spieth served that purpose well enough. While McIlroy had clearly honed his game in Valhalla - the hall of the Gods, not that godawful course in Kentucky - Spieth must have taken the low-rent option. Off the tee, Spieth sprayed the ball left and right, then couldn't sink a putt to save himself. How on earth he managed to end up one-under-par was one of the mysteries of the day. McIlroy, meanwhile, cruised on serenely. His birdie putt at the first lipped out, but he made up for it at the second, delivering what most observers considered to be the shot of the day.

In practice, McIlroy had played 3-wood off the tee at the second. Yesterday, his inner calculator mashed up a few numbers and told him he would be risking a trip into a bunker if he used that club again.

He dialled back to a 2-iron and placed his ball safely in the middle of the fairway, 190 yards short of the pin. What followed was a sublime demonstration of his skill. Caddie JP Fitzgerald handed him a 6-iron; two practice swings and one solid contact later, the ball was sitting just a few inches from the hole. The tap-in birdie got his round moving.

McIlroy's next great shot was at the par-5 fifth. Up to that point, he had been taking irons off the tee, but this time he reached for his driver and unleashed every ounce of power he had. The fact that his ball came to rest 354 yards up the fairway was impressive enough, but the fact that it was 110 yards ahead of the effort of playing partner Hideki Matsuyama (who, in fairness, had deliberately laid up short of some bunkers) was remarkable.

And so it went on. McIlroy birdied the fifth to move to two-under then the sixth to reach three-under and take a share of the lead. At that point, he was on the same mark as nine other players, but a gap was soon to open up.

McIlroy birdied the 10th and 12th, then moved to his six-under pace-setting mark at the 16th, where he floated a perfect pitch from a greenside bunker then tapped in from two feet. Along the way, he enjoyed a few strokes of good fortune - on top of everything else, he seems to have a gift for finding the least rough patches of rough on the course - but there was payback at the last when he had a bad lie in another bunker and had to play out sideways.

"I did get fortunate," he admitted at the end. "I got a couple of good breaks. But luck, bad bounces, good bounces, it all evens out at the end of the week. In the first round, I was more on the side of a little lucky than unlucky."

But what of round two? The starkest statistic in golf today is the one that measures the disparity between McIlroy's Thursday and Friday scores. This year, he is an aggregate 55-under for Thursday rounds and 15-over for Fridays. At the Aberdeen Asset Management Scottish Open last week, he began with a course-record 64 and then followed it up with a humiliating 78, a staggering turnaround.

The Hoylake forecast suggests storms this afternoon, which won't do McIlroy's cause much good. But he was sanguine about his prospects.

"When you go back out on a Friday you know what you can do on the golf course," McIlroy shrugged. "So you're going out with some expectations compared with when you go out on Thursday without any."