The country singer was joined onstage by T.I. for a performance of the hit, originally sung by Rihanna.
Taylor Swift, 21, keeps surprising her fans.
After welcoming Usher on stage during her concert at the Philips Arena in Atlanta the night before, the singer teamed up with T.I., 31, for a rendition of Rihanna’s Live Your Life.
“LOUDEST screams from the crowd, 14,000 people, hands in the air,” Taylor later Tweeted about the experience.
T.I. was released from prison in August after being sentenced to 11 months in October 2010.
The rapper is officially free since September 29 and has enjoyed its third day of freedom on stage with Taylor Swift.
Watch the duo’s performance filmed by a fan.