Beyoncé's Grammy Awards performance costume didn't just look like lingerie -- it was lingerie.

The centerpiece of the songstress' oh-so-sexy stage wardrobe was the "cage" vest from swanky underthings designer La Perla. (For those daring enough to rock Bey's style, the vest costs $332 at La Perla's Madison Avenue shop, a rep for La Perla said).

For her risqué performance of "Drunk in Love," the 32-year-old hot mama rocked the vest over a bra, a sheer top, a pair of booty-baring briefs and Saint Laurent by Hedi Slimane crystal beaded tights.

Hubby Jay Z, who joined her for the performance on Sunday night, was definitely appreciative of his lady's look (and so much more). When accepting an award for his tune "Holy Grail" later in the night, the rapper thanked God for "putting that beautiful light of a young lady in my life."