"I hear you've been telling people that you're the best a cappella singer town," Kendrick says, clearly not allowing that to stand -- even if Corden has starred on Broadway, won a Tony and acted with her in that little musical movie Into the Woods.
The British comedian clearly had to accept the challenge after Anna yelled, "I think this audience wants to see me kick your ass!"
Throwing on a track suit bearing his name across the back, Corden, 36, was joined by The Philharmonics for a rendition of *Nsync's "Bye Bye Bye."
Not to be outdone, Kendrick, 29, challenged him with Ludacris' "Move Bitch Get Out the Way." After Corden followed-up with Bell Biv DeVoe's "Poison," the Pitch Perfect 2 star sang Pat Benatar's "Love is a Battlefield."