Christina Aguilera stole the spotlight during a contestant's audition on "The Voice" last night -- by joining in as she sang "I'm Going Down."
After Aguilera picked Sera Hill to be on her team on last night's episode, the mentor told her "I've really been waiting for something to come along and excite me like you did, to the point where at the end I just wanted to grab a mic ad get up there and sing it with you."
And that she did.
Aguilera picked up a microphone and the two sang a great duet of the song -- one that proved Christina still packs some impressive pipes.
Check it out above. Is there anyone you're rooting for so far on the show?