In the traditional white-clad number, the top Idols rocked and rolled all over Pink's "So What."
Resuming their rivalry right where they left off, the judge and the half-dressed hopeful combined talents on Mariah Carey's "Vision of Love." Then, for good measure, DioGuardi ripped open her dress.
Not only did the reigning champion perform a moving version of his song "Permanent," he even got to present Adam and Kris with brand-new cars.
The outcome still to be decided, the two competitors kept up their good-natured competition, winning plenty more fans in the process.
Mraz said backstage that he was pulling for Kris Allen: "Anyone who is Jason Mraz-y, I kind of have to support that."
What brought the Queen out for a duet? "Because it's American Idol! Outside of the Super Bowl and the presidential inauguration, I don't think I've been in front of a larger audience," she said backstage.
In a match-up of multihued hairdos and questionable leg wear, these two talents delivered a low-key performance of Lauper's "Time After Time."
On "Kiss a Girl," these two good-natured performers meshed like they'd been jamming together for years.
After pounding out a medley of the group's hits with Adam, the band's star-eyed singer Paul Stanley said backstage, "Nobody lost tonight. These are two champions."
The Dutchess and the Black Eyed Peas showed what pop stars look like. They look good.
As much as we would have loved a duet on "Brick House," these two smoothies delivered a frothy pop cocktail on "All Night Long," a huge hit for Nicole Richie's dad.
In one of our favorite moments, the multitalented Martin sat in on "Pretty Flowers," a tune he wrote. His pick to win? "I know it's a long shot, but I'm hoping I do."
And really: What better night to break out the bombast with a version of "We Are the Champions"?