Christina Aguilera and Lil' Kim Perform 'Lady Marmalade' in Jaw-Dropping Show

Several thousand Christina Aguilera fans at Radio City Music Hall were treated to the surprise of [...]

Several thousand Christina Aguilera fans at Radio City Music Hall were treated to the surprise of the decade Wednesday night when Lil' Kim joined the pop icon to perform their no. 1 hit cover "Lady Marmalade."

christina-aguilera-lil-kim_getty-Kevin Mazur : Contributor
(Photo: Kevin Mazur / Contributor, Getty)

The two belted out the Patti LaBelle song, for which they won a Grammy for best pop collaboration with vocals with Mya and Pink, during the first of Aguilera's two sold-out New York City shows on her much-anticipated Liberation Tour. Not only did Aguilera and Lil' Kim collaborate on the 2001 song, but they also worked together again in 2002 on Aguilera's Stripped track "Can't Hold Us Down."

Ever since Aguilera, Lil' Kim, Pink and Mya took the stage at the 2002 Grammys together, the idea of a live reunion has been every fan's dream.

Mya opened up about the recording session earlier this year in an interview with Entertainment Tonight Canada. "But no, I don't remember any cat fight, we just got the job done. And we came to give a show at the end of the day. So it was a lot of fun and I really hope that we can reunite and do the song," she said, injecting hope into many a fan's heart.

While in the midst of singing the fan-favorite song, Aguilera brought out the rapper, telling the crowd, "We got a surprise — Lil' Kim, Lil' Kim, Lil' Kim!"

The 44-year-old rapper then appeared decked out in a sparkling gray bodysuit with sheer paneling.

But the show's surprises didn't stop there. After singing the ballad, "Unless It's With You," Aguilera helped facilitate a marriage proposal onstage, a tradition she started late last month when her tour kicked off at the hard Rock Live in Hollywood, Florida.

Plus, the songstress brought on A Great Big World to perform "Say Something" — and Bill and Hillary Clinton were spotted among the concertgoers. They even snagged a backstage photo with Aguilera.

bill-clinton-hillary-clinton-christina-aguilera_getty-Kevin Mazur : Contributor
(Photo: Kevin Mazur / Contributor, Getty)

The Liberation Tour, produced by Live Nation, is Aguilera's first tour in more than a decade and sticks around in New York for a second show at Radio City. The show wraps up in St. Petersburg, Florida in November.

The setlist includes many songs from her new album Liberation, including "Fall in Line," "Maria" and "Accelerate" — as well as other fan-favorites like "Fighter," "Beautiful," "Ain't No Other Man," "Genie in a Bottle," "Can't Hold Us Down," "What a Girl Wants" and "Come on Over (All I Want Is You)."

After her show in Florida last month, Aguilera shared a message about being back on tour.

"What an amazing warm welcome back to the stage after 10 years (too many!)— felt like coming HOME again!! Thanks to all of you in Florida for your beautiful energy. I feel fulfilled and alive and cannot wait to see you Fighters in New Jersey on Friday," she wrote.