When Neiman Marcus calls, designers come running. That seems to be the mantra of top designers at Fashion Houston.

Zac Posen, who thrilled a near-capacity crowd at the Wortham Theater Center Tuesday night with a glamorous collection of entrance-making evening gowns, is among seven designers who agreed to show their collections at the third annual edition of Fashion Houston because the luxury retailer asked them to.

"They were the first people to take me to Texas," Posen recalled about how Neiman's showcased his collection in Dallas and then Houston more than a decade ago.

"I was a baby. I probably just met the Sarofims and then Becca (Cason Thrash) and then I met Lynn (Wyatt). It began an exploration of me studying the history of the great American dressers and the Schlumbergers and understanding how (America's first couturier) Charles James must have worked, trying to search down those gowns in the archives."

Although Posen has been in the fashion world for what seems like forever, he is only 32. But he has a soul of a classic designer, with an endless fascination for detailing how a garment is made.

"It's obsessive for me. I think construction is something that is timeless; it's a deep exploration for me," he said. "I think construction in fashion is its purest form and from there you can elaborate or decorate to whichever level you need to. It's taking a line on a walk on the body."

Many in the audience, including front row fashion regulars Diane Lokey Farb, who will be honored as Fashion's Houston Style Icon Thursday night, last year's honoree Becca Cason Thrash, Lucinda Loya, Ericka Bagwell, Joyce Echols and Nancy Marcus Golden, were in awe of the collection Posen sent down the Fashion Houston runway.

It included 29 pieces, ranging from floral day dresses to many of the jaw-dropping gowns from his spring 2013 collection that was shown in New York in September, along with several items —tightly fitted suits, slacks and peblum blouses with sharp, architectural lines — from his resort collection that will appear in stores soon.

In New York, supermodels Naomi Campbell, Coco Rocha, Alek Wek and Karolina Kurkova rocked the runway in the Posen gowns while in Houston, local models did the same, giving credence to the belief that clothes make the model, not the other way around.

Posen's glorious gowns transformed the models into long-necked swans, as they glided down the runway in a regal manner. Some of the stately bearing might have had to do with the construction of the gowns that tightly holds the body in and the satin fabric that enhances the attitude.

In each look, Posen's painstaking detail shone through, whether it was in a cadet blue duchess satin tea length dress with scalloped sides, a gunmetal gray gown with a fishtail hem that rippled when the model moved or a navy gown dotted with tiny embroidered flowers.

The designer, who wore a burgundy suit that matched the color of the Wortham lobby, took a bow to a standing ovation. Afterwards, he gathered in the Green Room with the models, artfully placing them around him to frame a shot for photographers. When they seemed a little too artificially posed, he yelled out, "Smile. Hands up!" And they playfully complied.

Posen will make a personal appearance at Neiman Marcus at 1 p.m. Wednesday.