Miley Cyrus Liked Katy Perry's Kiss, But Which Celeb Really Had Her Fangirling?

Christina Aguilera, Khloe Kardashian and more hit up the Bangerz Tour ... including another special Disney child star.

It seems like Katy Perry and Miley Cyrus had an A-list audience witness their steamy smooch.

On Saturday, Cyrus took over Los Angeles' Staples Center for her Bangerz Tour, and halfway through the show, she planted a big kiss on the fellow pop star.

However, Perry wasn't the only celebrity to get in on the Miley action. Wayne Coyne from Flaming Lips joined Miley onstage for a performance of the band's "Yoshimi Battles The Pink Robots Part 1."

Other stars came out in droves to witness the singer twerk, slide down an inflatable tongue and straddle a giant hot dog. The newly engaged and possibly pregnant Christina Aguilera gave a big "cheers" to Miley, who reminded "The Voice" mentor of her "Dirrty" days.

"Keeping Up With the Kardashians" star Khloe got a little backstage loving from Boo the Bear.

Khloe's sister Kendall was reportedly also in attendance, as well as One Direction's Harry Styles, but no word if the rumored couple were spotted together.

Max George, who is going on hiatus from The Wanted following their tour, was so impressed by Miley's onstage antics that he thought he was "tripping."

Joel Madden tweeted that Miley "puts on a great show." MTV Artist to Watch singer Jake Miller tweeted, along with a photo of them together, that she "killed it." Miley's dad, Billy Ray, said that she had the Staples Center "rockin."

However, out of all these A-listers, which also included Diane Keaton, Sarah Paulson and Kellan Lutz, Miley was completely "fan girling," over one attendee in particular: Lizzie McGuire herself, Hilary Duff.