'American Idol' performance spoilers below!
Kara Dioguardi unveiled her bikini body during the big two-hour finale show. She joined 'bikini girl' Katrina Darrell during a performance for an epic sing off, after the pair butted heads during auditions. At the end of the song the newest judge unzipped her dress to flash a black string bikini she had on underneath.
Afterward, Ryan applauded her and said that by flashing the world, Kara won a bet and a donation to charity.
Follow HuffPo Entertainment On Twitter!