The Top 13
In the traditional white-clad number, the top Idols rocked and rolled all over Pink's "So What."
Kara DioGuardi & Katrina "Bikini Girl" Darrell
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.
David Cook
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.
Adam Lambert & Kris Allen
The outcome still to be decided, the two competitors kept up their good-natured competition, winning plenty more fans in the process.
Alexis Grace, Jason Mraz & Anoop Desai
Mraz said backstage that he was pulling for Kris Allen: "Anyone who is Jason Mraz-y, I kind of have to support that."
Lil Rounds & Queen Latifah
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.
Allison Iraheta & Cyndi Lauper
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."
Kris Allen & Keith Urban
On "Kiss a Girl," these two good-natured performers meshed like they'd been jamming together for years.
KISS & Adam Lambert
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."
Fergie
The Dutchess and the Black Eyed Peas showed what pop stars look like. They look good.
Lionel Richie & Danny Gokey
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.
Megan Joy, Steve Martin & Michael Sarver
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."
Queen's Brian May & Kris Allen
And really: What better night to break out the bombast with a version of "We Are the Champions"?