It was 76-year-old Florence Henderson's night to shine as "Queen Mom" on ABC's "Dancing With the Stars."

As part of StyleList's new weekly behind-the-seams costume recap with the show's Emmy-winning costumer, Randall Christensen, we asked for the inspiration behind some of our favorite ballroom looks. Our top pick just happens to be Christensen's as well: the mature duo of Florence Henderson and Corky Ballas!

The former Mrs. Brady wore an exquisite black ball gown featuring a dramatic side slit that revealed ample portions of her age-defying legs plus a bright flash of red lining.

Her embellished dress was accented with a stunning crystal neckline that created the illusion of a multistrand necklace. Her dashing professional partner had coordinating red accents on his lapel.

"What a sophisticated, glamorous -- and yet sexy -- look for our Queen Mom," Christensen tells StyleList. "Our inspiration came from various silhouettes of some of Hollywood's most famous and glamorous stars: Cyd Charisse and Audrey Hepburn. And when Florence struck that opening pose, slit skirt peeled open... Need I say more? She took my breath away!"

Judges' score: 19 out of 30; costume score: A perfect 10!

Audrina Patridge's super-sexy, bright-blue costume featured a rhinestone-grid mesh, bare midriff, chiffon skirt, and ostrich boas and coque-feather strands that made the dress soar. "I have to say she makes me look good," says Christensen.

As for Patridge's partner Tony Dovloani's dramatic "pleather-timmed" suit, Christensen took inspiration from the Paris runways and "The Matrix" films. "It was edgy and fashionable," he says.

Mike "The Situation" Sorrentino's buttoned-up, military-inspired jacket was a deliberate attempt by Christensen to make the reality star seem more serious.

It "calmed down his bit of being a rebel" while suiting his youth, short-cropped hair, and Christensen's desire for a "refreshing change from the suit/tuxedo" options. And even better, it didn't reveal "The Situation's" often-exposed six-pack!

His professional partner, Karina Smirnoff, wore a patriotic frock bedazzled with bright blue stars that was a tribute to the Donna Reed days. The spin was "quite clever and her idea!" Christensen says.

Christensen was left almost speechless by the sexy, gold-fringed minidress that accentuated dirty dancer Jennifer Grey's amazing body (is she really 50?). "Who needs to say anything more than 'Wow!'" says Christensen. "Gold fringe has never looked so hot."

Watch "DWTS" tonight at 9/8 c on ABC to see who will be the second celebrity eliminated.

Meanwhile, read about the "trick" costume Christensen created for Bristol Palin to wear on the season 11 premiere.