While [artist id="3274550"]Katy Perry[/artist] and "Glee" guest star Darren Criss have both had [article id="1652691"]chart success with Perry's "Teenage Dream,"[/article] the two had yet to perform the track together. Criss originally performed the tune on the hit Fox show, while Perry released it earlier this year as the second single from her album of the same name.

The two finally took the stage together for the first time at the Trevor LIVE annual fundraising event held at the Hollywood Palladium on Sunday night. Criss, dressed in a suit, was performing the track with the show's Dalton Academy Warblers, when Perry, dressed in a sequin dress, hit the stage to belt out the last bit of the tune. Footage of the performance hit the Net shortly after the event.

Other performances for the night included a spoken-word number from Queen Latifah as well as the [article id="1645324"]Hollywood Bowl cast of "Rent"[/article] singing "Seasons of Love" and "Will I." Kathy Griffin was honored by "Glee" star Jane Lynch for donating her paycheck from an L.A.-area stand-up gig to the Trevor Project, a nonprofit organization that offers suicide-prevention services to lesbian, gay, bisexual and transgender youth.

Some of the other names in attendance included Neil Patrick Harris, Jesse Tyler Ferguson, Rashida Jones, David Arquette, Sarah Silverman, Taye Diggs, Idina Menzel, Kate Walsh, Wayne Brady, Justin Long, Joe Manganiello, Kristin Davis, Brittany Snow, Amy Poehler, Will Arnett, Josh Duhamel, Anna Kendrick, James Marsden and Jessica Alba.

"She's been really sweet," Criss said of Perry's support after his "Teenage Dream" performance on "Glee." " ... It's a great tune. I really lucked out that I got to sing that song. I mean, you've gotta sing what they give you."

Whose version of "Teenage Dream" do you prefer: Katy's or Darren's? Or do you prefer their joint version? Let us know in the comments!