For years, Kris Van Assche has been preaching the gospel of sport-meets-suit. For Spring, that idea has run rampant over the runways. Every designer out there is feeling the pull of sportswear. It's offered a bit of context for the ideas Van Assche has long been tweaking. And with one of his strongest collections in seasons, he finds himself part of the pack.

"These young guys who used to be mega into sportswear," he said backstage after the show, "they have the great eye for detail. They turn out to be the best dressed." His clothes still do, as they always have, skew very young. But his own appreciation for the finer details of sportswear—the snap buttons, the functional pockets, the ease of elastics—worked well here when transposed to the context of the traditional men's wardrobe. He spliced the two codes, calling the result Cognac Sport—cognac for the color of men's traditional leather goods. His pull-on anorak came in piqué cotton like an evening shirt; other versions, with zip pockets on the front, the sort bike messengers use, came in suiting fabric, worn with tailored shorts. Elsewhere, he used the symbols of menswear, from the crocodile of fine accessories to the polka dots of a tie or pocket square, writ large. Croc-knit sweaters were a sporty deflation of luxe; croc-embossed backpacks and gym bags, even more literally so.

A few patterned pieces felt at odds with what Van Assche called the "anti-dandy" spirit of the collection, but the strongest pieces had a bright, solid clarity, the sort that radiates, without regard for class or caste, from the classics of the aristo wardrobe as much as from the world of sport. He was remembering fondly that for his first show nine years ago, he accessorized his looks with Adidas Stan Smiths. He's honed his touch since then, but the spirit remains. Not only remains but sets down roots: Van Assche's first Paris boutique opens on Rue Saint-Roch this week.