As thousands of eager eyes peered down the 18th fairway into a blinding sun, a red-shirted figure gradually emerged from the haze. "Rory! Rory! Rory!" the chant began, after yet another expertly-cut drive onto the prevailing south-west wind had found the middle of the fairway.
Half-an-hour earlier, another red-shirted challenger had experienced a far more muted reception on reaching the final green. Only the odd, almost plaintive cry of "Come on Tiger!" gave any hint of his one-time pre-eminence in the game. American golf was about to confirm the arrival of a stunning, new hero.
Intense sunshine, and the backdrop of unkempt, random areas of sand, seemed to lend an almost surreal dimension to the McIlroy conquest. And the accompanying sound grew in intensity when his approach shot landed pin-high, a few inches into the left fringe of the final green. So began a victory walk very different in scale to the iconic climax of an Open Championship, yet comparably thrilling in its intimacy.
Facing the players directly behind the green, was the formidable Wanamaker Trophy on a wooden stand, reviving memories of a Monday morning outside Detroit four years ago, when Pádraig Harrington struggled to cradle it and the Claret Jug in either arm, after capturing back-to-back Majors. And he, too, won the PGA with a closing 66 and by completing 27 holes on the Sunday.
For the moment, however, McIlroy's arms were employed acknowledging the cheers and applause, while he smiled broadly beneath his familiar, unruly mop. And when the gods also signalled their approval by guiding a 20-footer into the cup for an improbable closing birdie, he tucked the winning scorecard into his hip pocket and shared a long embrace with his father Gerry. Whereupon tears of relief flowed freely.
It was a lot different from Congressional, where the boyish enthusiasm of the champion was now replaced by patent self-confidence. And we could but marvel at the extraordinary maturity which can take place in the short space of 14 months, when you happen to be in your early twenties.
Amid the scramble of well-wishers in the score-recorder's area, David Feherty had just completed his on-course duties with the CBS Network. "That might have been the greatest round of golf I've ever seen," he said. "I've seen a lot in the Tiger Woods era, but I don't think I've ever seen anybody take charge of a golf course as difficult as this one is, and play it as clinically."
This was not to overlook the astonishing, 15-stroke victory by Woods in the 2000 US Open at Pebble Beach, but on that occasion, Feherty noted he had entered the final round eight strokes clear of his rivals, whereas McIlroy was only a vulnerable three ahead. And even Pebble Beach is a lot less daunting than the Ocean Course which is rated the toughest in the US.
Feherty, who learned his golf at Bangor, where McIlroy's coach Michael Bannon retired recently as professional, went on: "Today, Rory didn't give anybody even the vaguest squeak at catching him. At no point did anybody other than Rory look like they had a chance of winning.
"When you get that far in front, most of the time players are thinking of a way to lose and they'll proceed to miss a shot here or there. When he did miss one, however, it was in the right place. And he proceeded to make every single putt. Every single one. I've never seen that before."
When I reminded him that on the same terrain in the 1991 Ryder Cup he himself had produced the best golf of Sunday's singles with an approximate level-par for 17 holes when beating reigning US Open champion Payne Stewart by 2 and 1, he responded: "If somebody had told me that 21 years from then, someone could play a round like this, I would have laughed in their face. I tell you I couldn't be prouder of that wee man. Couldn't be prouder."
After McIlroy emerged from the scorers, Graeme McDowell was there to congratulate him, just as he had been at Congressional, where he had watched the closing moments from beside the 18th green. "I told you to go easy on us," he now teased. Then, with a huge smile: "Well done, anyway."
And still, the plaudits poured. Having departed Kiawah the previous Wednesday in the knowledge that his work was done, Bannon wasn't surprised at the outcome. "When Rory and myself arrived at Kiawah on the Monday, he told me he really liked the place," he said. "He liked its length and the wide fairways. And he knew the paspalum greens from being based at The Bear's Club, which has the same grass."
Then there was the transformation wrought in the player through a meeting with his putting coach Dave Stockton the previous week. "I came here with a different attitude, having got a spark back in my game in Akron," said McIlroy. "I would just go out and enjoy it and see what happened."
So, all the ingredients were in place for a perfect, McIlroy scoring storm.
On first learning how to associate a child's obsession for golf with the leading exponents of the game, a remarkable lad from Holywood referred to himself as Rory "Nick Faldo" McIlroy. Then, as a still cherubic 12-year-old, he became an eager pupil in the "Faldo Series". And five years further on, he stood as a golfing equal beside his one-time hero at Ballyliffin, in an exhibition match to mark Faldo's upgrading of the Old Links there.
That was in June 2006. Though the teenager had grown two inches in the previous 12 months, he was still a relatively slight 5ft 9ins and 10st 7lbs, compared to Faldo's powerful, 6ft 3ins frame. The Englishman wondered about his young challenger, who would go on to retain the Irish Close title at The European Club a week later.
"I learned two things that day," the six-time Major winner said last week. "I learned that Rory could play a bit (he beat Faldo 67-69). And I could see close up, the most remarkable hip action of any player in the modern era." This, from a keen student of golf who, when the prodigious ball-striking of Tiger Woods had captivated the game, talked of the American's "serious shoulder speed".
With considerable muscular violence, however, Woods lashed at the ball to achieve distance, leading to serious problems to his left knee. McIlroy, on the other hand, derives his length from a different, safer source. And Faldo took the trouble of analysing it. He also noticed at Ballyliffin that McIlroy's instruments of battle included four wedges, reflecting an emphasis on the short game, the so-called money shots which were to serve him so well last weekend.
In fact, the quality of his short game delivered some remarkable statistics at Kiawah. Over the four days, his putting return was 29, 30, 27 and 23. He had no double-bogey and no three-putt in 72 holes which comprised 20 birdies, seven bogeys and 45 pars. All of that against a background of 48 out of the 72 greens hit in regulation, which was understandably modest given the conditions and the difficulty of the course. And all the while, he was glorious to watch, especially in a final round which was probably the best I've seen at this level.
"He's got this physical anomaly, if that's the right word, in the way he can move his hips," said Faldo. "When they go on computers now, they show that he can move his
hips 717 degrees per second (or 70 degrees of rotational movement in the time Usain Bolt would cover one metre). This is literally twice as fast as anyone else. In fact, Rory has twice as much range of motion and twice the hip action of his rivals. That's why he belts it as far as anybody."
He added: "Then there's the wonderful elasticity of his swing and his rhythm, which was always there. I played a practice round with him before the 2007 Open at Carnoustie and he put his waterproofs on. And I remember thinking that it was the best swing I'd seen in waterproofs."
All great players bring something personal, something special to the game. According to Tom Watson, Jack Nicklaus was easily the best he had seen at negotiating his way around a golf course. And Woods at his best brought an unrivalled intensity to tournament play, while being probably the greatest putter of the modern era.
Yet despite unique physical gifts and wonderful skills, McIlroy is unlikely ever to become a prolific winner in the Woods mould. Nor will he make himself a hostage to fortune by pinning a Major target on his bedroom wall. With his ties to his native place, an attractive girlfriend and his open lifestyle, he's too "normal" for such an intensely focused career.
Asked how many Majors he aspired to, the champion replied: "As of now, I'm just looking for my third one. I'm not trying to emulate anybody or match anyone. I've got my second, which feels unbelievable and I'm going to enjoy it. And at the start of next season I'll be working towards my third. And hopefully when I get that I'll be working towards my fourth."
Along that journey of immense promise, there's a good chance he will continue to produce performances of the highest quality when the mood takes him. And on those occasions when he really hits the peak of his powers, we can anticipate further, fresh standards for the Major championships. Which is a thrilling prospect.