Tay performed a few of her 1989 hits AND brought back a few songs from her Red album. She had the entire audience dancing and singing along with her.
Check out 6 ways she was the Belle of the iHeartRadio Jingle Ball!
1. She showed up to the red carpet in this STUNNING little number (Tay, can we borrow that sometime?):
2. She transformed herself into full holiday mode in this adorable Christmas plaid outfit:
3. She sang "Welcome To New York" IN New York ... IN NYC's most iconic venue, Madison Square Garden. #Winning
4. THIS HAPPENED. New Blonde besties? Maybe a collab will come from this?
5. At midnight, it was her 25th BIRTHDAY!! HAPPY BIRTHDAY TAY!
6. She had the ENTIRE Madison Square Garden SHAKING IT OFF!
Photos: Getty Images & Andrew Swartz for iHeartRadio