Thursday’s launch of Matthew Williamson for H&M had the hallmarks of the retailer’s previous designer collaborations, albeit toned down a notch. Yet if lines outside stores were slightly shorter and crowds a bit smaller and calmer, the demand exceeded supply in many cases.

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This is the first time the retailer has introduced a designer collection in the spring, being launched in 200 stores. It’s also the first time H&M has done a two-part launch. As an encore, the chain on May 14 will introduce in all of its 1,700 stores a more populist line by Williamson, with 25 pieces for men and 30 for women. Besides apparel, the collection will include bikinis, sunglasses, flip-flops, beach bags, sarongs and towels.

“Within the first 11 minutes, half the garments were sold,” said Jennifer Uglialoro, an H&M spokeswoman, standing in the store at 640 Fifth Avenue at 51st Street. By 10 a.m., only a small area sparsely stocked with Williamson items remained. Half of the main floor, which had been devoted to Williamson’s designs, had been replaced with spring merchandise from the regular H&M collection, leaving no hint of the peacock feathers, sequins, ruffles and leather that had been on display.

“It was supposed to have a longer shelf life,” said Uglialoro. “It’s very hard to tell.”

She speculated the collection sold out so quickly because of its size, only 20 garments and a few accessories. The last collaboration, with Comme des Garçons, had 25 to 30 pieces of apparel plus accessories for women and the same amount for men.

Williamson’s collection was offered in eight H&M stores in the U.S., including three units in Manhattan and one store each in Los Angeles, San Francisco, Chicago, Boston and Atlanta.

“It wasn’t as ‘Wow,’ ” said an H&M employee at the Fifth Avenue and 51st Street store. “It wasn’t as intense. It definitely wasn’t as ‘wow’ as the fall designer launches. They’re usually more well-known. There weren’t the usual brawls.”

Less chaos in general meant fewer people grabbing merchandise out of each other’s hands, stripping outfits off mannequins and accosting salespeople carrying replenishments.

Thursday’s collection, which features cashmere, leather, sequins and embroidery, is priced from $49.90 for shorts to $349 for a ruffle gown. The long scarf and the outfit featured in the ad campaign — a long ruffle dress and short biker jacket — were the first items to sell out. The launch had been bolstered by print, billboard and online advertising campaigns.