Taylor Swift has been covering Justin Bieber's "Baby" during her latest concert tour, but last night in L.A., she did one better!
Instead of just singing his song, Swift was able to get Bieber himself to come out and duet with her on stage -- sending the crowd into hysterics.
The show was Swift's first of four sold out concerts at the Staples Center ... no word on if Bieber (or maybe someone else) will pop up on stage tonight.
Check out the duet, shot by a fan, above!
