Fashion had seen nothing like it for years. Outside in the street, there was hysteria. Inside, the industry's great and good—Alaïa, Elbaz, Jacobs, Theyskens, Tisci, Van Assche, Versace, von Furstenberg—gathered to see Raf Simons debut his first haute couture collection for Christian Dior. That it would be a success seemed a given, what with the evolving polish and confidence of Simons' "couture trilogy" for his previous employer, Jil Sander. That it would be such a triumph was a thrill. The avant-garde outsider from Antwerp insinuated himself into the hallowed history of haute couture with a tour de force that had both emotional and intellectual resonance. As the man himself said, "A shift is happening."

About that outsider thing: It's a position that has always loaned a crystal clarity to Simons' vision and has helped him to the purest interpretations of his inspirations. Here, he used that unusually heightened sense of focus to reflect on Christian Dior as architect, a notion that dovetailed neatly with his own obsession with construction. The first look—a tuxedo whose jacket was shaped after Dior's iconic Bar jacket, one of the most distinctive silhouettes in fashion—established an innate compatibility that reached across a half-century.

Simons has been engaged with this world for a while. Dior was obviously the guiding spirit of his fascination with midcentury couture (see the Q&A here) during his last seasons with Sander. But he approached an actual couture collection with an appropriate balance of reverence and iconoclasm. One key silhouette could best be defined as a full-skirted classic ball gown truncated at the peplum (a quote from a 1952 collection, according to the run of show), its skirt replaced by black silk cigarette pants. The formal past, the streamlined future, meeting in the middle. It was the same with the traditional Bucol silks woven to represent a painting, drips and all, by Sterling Ruby, one of the contemporary art world's hottest properties (and a Simons favorite). Past and future met again in an evening ensemble that matched the athletic ease of a citron silk knit to the grandeur of a floor-sweeping silk skirt. And the veils that Stephen Jones contributed to the finale may have been from Paris in the 1930's, but there is timeless allure in that look.

Simons returned to the flared hip of the Bar with a deep-pocketed coat-dress in red cashmere as well as a strapless dress in the same heartbreaking shade of pink that launched his last Sander show. That was the kind of subtle personal flourish that married his own story to Dior's history. It also underlined how much of an asset Simons will be not just to Dior but to couture itself. He can't help himself; he will bring a heart-on-his-sleeve human dimension to this remote and rarefied world.

But as he proved today, he certainly won't be doing it in a low-key way. Christian Dior's own obsession—flowers—was translated into salons lined ceiling to floor with panels of blooms: delphiniums in the blue room, orchids in the white room, mimosa in the yellow room, and so on. More than a million all told, making a gorgeous architectural abstraction of nature. There's some kind of metaphor about creative processes in there somewhere, but it's simpler to leave things with Simons' own definition of the day: "a blueprint."