When it came—and it's been a long time approaching—Valentino Garavani waved his last goodbye in a room literally lined with the ultimate image of his contribution to fashion: the gorgeous red gowns he has worked from first to last. It was just one red gown, actually—projected on the walls and worn by all of the models who filed out moments before Mr. Valentino took his final walk down the runway to a standing ovation. Uma Thurman was there to salute him, along with Lucy Liu, Alber Elbaz, Miuccia Prada, Nadja Auermann, Eva Herzigova, and Claudia Schiffer.

Valentino is nothing if not classy, though, and despite the tears among his audience, friends, and staff, he exited the stage without overplaying the sentimental moment. Maybe he felt the memory of his last haute couture—his legacy for the future—shouldn't be overshadowed. Right enough: What he showed was a fitting conclusion to 45 years of celebrating the happy side of femininity and—at least for one young woman in the audience—a lesson in technique, joie de vivre, and the principles of old-school glamour. The woman in question: Alessandra Facchinetti, the ex-Gucci designer who, from now on, will carry the Valentino flame.

It wasn't a retrospective, but the essence was all there: the Val way with double-faced coats and little luncheon suits; the fragile beaded chiffons; the cocktail sheaths; the love of lace, flower prints, and succulent satin bows; the magical draping; and the manner in which he cut a column and arranged an asymmetric shoulder strap just so. If it didn't all belong to the contemporary swim of things, there were standout moments that were both relevant to fashion right now and timelessly gorgeous—an airy pink gazar trapeze coat over a fondant orange shift; a white tailored dinner dress with a raised waist, short sleeves, and collar beaded in silver crystal; or a one-shouldered white satin dress with a knotted strap, splendidly walked by Natalia Vodianova. "Impeccable," of course, is the word—perhaps the one Valentino owns, above all other designers. He's a hard act to follow. But if Facchinetti captures that pristine state of fashion loveliness and turns it in a modern direction, she'll be heading on the right path.