The 34-year-old singer impersonated her fellow pop star during a Wheel of Musical Impressions segment with host Jimmy Fallon. Aguilera performed "Grand Old Flag" as Cher before singing "This Little Piggy" as Spears, and joined Fallon for the Golden Girls theme song as Shakira.
Aguilera and Spears met as Mouseketeers on Disney channel series The All-New Mickey Mouse Club, and rose to fame in the music industry at the same time. The 1993-1995 revival of the program also produced such stars as Justin Timberlake and Ryan Gosling.
Aguilera released her seventh studio album, Lotus, in November 2012, and returned as a coach on season 8 of NBC reality competition The Voice on Monday. Spears debuted Britney Jean in December 2013, and is currently in residence at Planet Hollywood in Las Vegas.
"I can say that each time I come back I feel like there are more additions that just work," Aguilera said of The Voice to The Hollywood Reporter. "What [the time away] does is let me step away and come back with a fresh perspective on things. I am excited to see what talent awaits this season."