Britney Spears Rocks Chic Black Jumpsuit on X Factor Finale

USMagazine, Thursday, December 20, 2012, 12:00pm (PST)

Britney Spears has been a fashion tour de force during her inaugural season as a judge on The X Factor.

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Night after night, the pop superstar wowed in form-fitting frocks, midriff-baring tops, and sexy minidresses that showed off her lean legs. But on the Wednesday, Dec. 19, show -- part one of the competition's two-part season finale -- the 31-year-old mentor kept her look modest and let her star contestant, Carly Rose Sonenclar, have the spotlight instead. Sporting a black Yves Saint Laurent jumpsuit, black-and-white heels, and a long Erickson Beamon beaded necklace, Spears was the picture of understated chic.

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Sonenclar, on the other hand, looked -- and sang -- like a true star-in-the-making. Facing off against Fifth Harmony and Tate Stevens for a $5 million recording contract, Spears' 13-year-old protege performed pitch-perfect renditions of Nina Simone's "Feeling Good," Leonard Cohen's "Hallelujah," and LeAnn Rimes' "How Do I Live" -- with Rimes herself!

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"I just feel like it's shocking how bright your star is, and we're going to win this," Spears told her contestant.

Later, after Sonenclar's cover of "Hallelujah," she added: "That performance alone is worth five million bucks, so you should get out your checkbook, Simon [Cowell]."

The X Factor finale aires Thursday, Dec. 20, at 8 p.m. EST on FOX.

This article originally appeared on Usmagazine.com: Britney Spears Rocks Chic Black Jumpsuit on X Factor Finale