In the chat show's game 'The Wheel of Musical Impressions,' Xtina mimicked her pop rival's signature raspy vocals by singing 'This Little Piggy' to the tune of her 1999 hit 'Baby One More Time.'

Through the twenty years since the feuding pair's Mickey Mouse Club days, Christina Aguilera must be very used to reporters bringing up Britney Spears in interviews - and even more rehearsed in knowing what to say to bat off any rumours of beef between them.

 

But the 34 year-old singer was taken by surprise when she was asked to impersonate her pop nemesis in a nursery rhyme re-take of Baby One More Time.

 

 

Talented Christina started the game off on a tame note, by crooning the Folgers coffee jingle in the throaty style of Cher - her co-star in 2010 musical flop Burlesque - and was followed by Jimmy Fallon's attempt at David Bowie.

But when the 'wheel' conveniently stopped at Britney Spears, Christina burst out laughing.

'You know Britney Spears?' Jimmy asked innocently.

'Little bit, little bit,' Christina replied, jokingly playing it down.

But it didn't take much coaxing for Christina to do a pitch-perfect, breathy impression of her arch-enemy - leaving viewers wondering if her imitation of her fellow pop princess might actually be a well-rehearsed party piece....

Jimmy Fallon heaped praise on Christina through fits of laughter, saying: "I loved that so much. That was amazing. It's hard to top that."

Christina finished off with a Shakira rendition of the Golden Girls themed tune - which the singer claimed she listens to every night.

But we're sure you'll agree that the Britney song was definitely the winning round!