Christina Aguilera's Britney Spears imitation was so amazing that it got "The Tonight Show" host Jimmy Fallon clutching his stomach as he laughed out loud.
They may have been rivals back in the day but the singing sensations go way back together. They were in Disney's Mickey Mouse club way before they started taking over the world in midriff tops in the 90s.
Despite knowing each other for a long time, fans haven't heard either one parodying each other.
The "The Voice" coach had her chance during Fallon's "Wheel of Musical Impressions" game.
Whether intentional or an inspired coincidence, Christina Aguilera's Britney Spears impression while singing "This Little Piggy" instantly became a huge Internet hit.
"This little piggy ate roast beef, went wee wee all the way home," bringing a totally floored Fallon to his feet.
"That was amazing! I loved that so much. That was fantastic!" Fallon gushed afterwards as he gave his guest a standing ovation.
Huffington Post was also impressed by the imitation, saying that the clip with will "completely blow your mind" and "drive you crazy."
At the same time, Popsugar said she "nailed it" and called her the "queen of impersonations."
She also did a rather impressive imitation of Cher and Shakira, while Jimmy Fallon did his best with David Bowie and Michael McDonald parodies.
Another celebrity who impressed the Internet with his impersonations of his peers is Benedict Cumberbatch. He tried to do "Harry Potter" star Alan Rickman, Sean Connery, Tom Hiddleston and even Taylor Swift.
Watch him compete with Jimmy Fallon on who makes the best Alan Rickman voice.
Also, tell us what you think about Christina Aguilera's Britney Spears impression! The hilarious clip starts at 1:47.
