Paddy O' Prado did his job by winning the Secretariat Stakes as the heavy favorite.
An emotional victory by Eclair de Lune, owned by Arlington Park chairman Richard Duchossois, in the Beverly D. only raised the bar.
Now the scene was set for the final act of the day: the coronation of Gio Ponti in the Arlington Million.
And when the defending champion made a sweeping six-wide move turning for home and pulled out to a 2-length lead in deep stretch, it seemed a foregone conclusion: the King was back.
Evidently someone forgot to tell Debussy and his jockey William Buick, who provided the "I didn't see that coming" moment of the day.
The pair waited out a tiring rival at the top of the stretch, dove between two horses running in place and down to the rail, and then showed more pickup than a mint-condition Ferrari to close the gap on Gio Ponti and win by a half-length in the stunner of the day at odds of 11-1.
And just like that, the King was dethroned. No police escorts back to the airport this time.
"We were too tight for room early, and I thought, 'Oh, no, we're not going to have room," Buick said of his road woes turning for home. "But then he got clear and he was able to run his race."
But even when he finally got room, not many in the crowd of 30,304 thought he would have enough to catch the defending champ in deep stretch. That included Debussy's trainer, John Gosden, who also had Tazeez (third place) entered in the race.
"I did not call him the winner at the eighth pole," Gosden said with a smile. "At that point I said, 'Well, Tazeez has run great and the other horse will run on to get fifth, fourth - oh, my goodness.' "
Perhaps it was a fitting end to the Beverly D.-Million daily double of Eclair de Lune and Debussy, seeing as how one of French composer Claude Debussy's most popular pieces was Clair de Lune.
But Gio Ponti's runner-up finish was anything but music to the ears of those who backed the 4-5 favorite.
"I thought I had enough to hang on," said Ramon Dominguez, Gio Ponti's jockey. "Once I got clear the horse was idling a bit, maybe looking at the stands or something.
"But the trip was great. I had a lot of horse turning for home; he just couldn't hang on that last sixteenth."
As good a trip as the favorite had, it was just the opposite for Debussy, but his young jock handled it like the veteran he isn't.
"He has a wise head for a 22-year-old," Gosden said of Buick. "He rides clever; he doesn't panic, which he certainly didn't do today."
Patience has been quite the virtue as well for Gosden, who has entered nine horses in the Million over the years, starting with Star Pastures in 1982. But he had to wait until Debussy's heroics Saturday to make it to the winner's circle.
"John Gosden and Ron McAnally (Eclair de Lune) are two very special trainers," Duchossois said at the postrace festivities. "They have consistently come here year after year, even if one of their horses didn't even have that great a chance. They are two of the greatest supporters we've ever had for the festival."
And like his friend Mr. D., who finally got his just desserts with a win in the Beverly D., Gosden at long last can call himself a Million champion.
"I've been trying to win this race for 28 years," he said.
And now he's the king.