Christina Aguilera was a surprise performer at the Justin Timberlake and Friends Benefit Concert, Timberlake’s annual benefit for the Shriners Hospitals for Children. Aguilera took the stage during the star-studded show, held at the Theatre for the Performing Arts in Las Vegas in the Planet Hollywood, where she was introduced by Timberlake as, “no contest, the greatest voice of my generation.”

Christina opened her set with her recent hit “Not Myself Tonight” from this year’s “Bionic.” She also performed her #1 hit “Beautiful,” the anthemic “Fighter,” and even alluded to her divorce while introducing the song “Ain’t No Other Man,” written about former husband Jordan Bratman.

“We’re gonna get back into some old stuff of mine, and this is a song I wrote at another time in my life but it’s called ‘Ain’t No Other Man,’” she told the crowd of thousands.