(Photos: Vince Bucci/Fox/PictureGroup)

Beyoncé lit up the stage on last night’s American Idol finale, wearing her sexiest costume to date. The ladies of AI performed a medley of her greatest hits and Bey, like the diva she is, later appeared from the top of a smoke-filled set of stairs to perform “Crazy in Love.” She showed off her toned thighs in a sparkling Ralph & Russo grey mini dress with a plunging neckline. To avoid any wardrobe mishaps, the dress was also a leotard of sorts.

The “Run the World (Girls)” singer hit the stage one last time to debut “1+1,” a ballad featured on her forthcoming album 4. She kept the same color palate, wearing an elegant grey gown with a V neckline by Zac Posen, and elaborate, jeweled chandelier earrings that occasionally peeked from behind her blonde tresses. She also wore a statement bracelet cuff that boasted more sparkle than her ring and earrings combined. Her look truly came together as she passionately belted out her most heartfelt lyrics of the song, “Make love to me.”