Watch out, Fergie! The pint-sized pop star pulls out all the stops when lip syncing to 2007 hit 'Big Girls Don't Cry'.
Justin, 21, put on an emotional rendition of Fergie's popular ballad for American TV show Lip Sync Battle.
Facing off against NFL star Deion Sanders, Bieber shirt lip synced his way across the stage, belting out lines, "We've got some straightenin' out to do....I'm gonna miss you like a child misses their blanket....But I've got to get a move on with my life....It's time to be a big girl now....And big girls don't cry."
Watch Justin lip synch below, for yourself!