Great fashion comes from designers who can fuse two apparently contradictory ideas together to create a synthesis that has never occurred to anyone before. That was the order of experiment—and risk—taken on by Nicolas Ghesquière at Balenciaga. He was aiming, he said, to make something new of "architecture and embellishment, sharpness and ornamentalism."

The show condensed Balenciaga past and present, starting with evocations of Cristobal's cocktail bubbles, creamily rendered in heavy radzimir and embossed silk, and then delivering the surprise—densely elaborated upgrades of Ghesquière's tailoring and drifty patchwork dresses.

It was what he called his "baroque rock star" pantsuits that delivered the biggest jolt of surprise. The strict planes of his familiar lean, nipped-waist, long-leg suits are now etched over in dark Wedgwood-like Jacquard patterns, and worn with high-neck frilled shirts. From there, Ghesquière made his way to light-as-air scarf dresses composed of panels of silk print, inserted with lace and cascading frills; glamorous black gowns, intricately worked in lace and chiffon, suspended from bra straps; and cream organza bell-shape dresses weighted with deeply flounced hems.

If all that sounds molto complicato, there was still more compressed into this brisk presentation. Ironically, those were the things of simple, wearable genius—gray knife-pleated kilts, ingeniously seamed in the back and worn with printed, jeweled rock-tour T-shirts—that made for a brilliantly chic take on this season's college-girl look.

It all ended up, though, with more baroque and froth: a full Louis XIV fantasy version of the Balenciaga jacket, with extravagant peplums and foppish lace cuffs, and boudoir lingerie paired with droopy bloomers. Those last looks were duds. But when a designer is determined to push creativity to the brink of newness, he's allowed the odd mistake.