"By coming to this show tonight, you are attending 100 percent of this year's tour dates," she told the star-studded audience.
Tay Tay's performance for the annual pre-Super Bowl party was strictly about the music, with little of the costume changes or special guest appearances that she's known for.
The 27-year-old popstar, dressed in a sequined and tasseled short black Versace dress, grabbed her guitar and sat at the piano for energetic performances of old and new songs, including her Fifty Shades
Darker duet with Zayn Malik, "I Don't Wanna Live Forever" -- although Zayn was not present, much to the disappointment of fans!
Swift also performed the song she wrote for Little Big Town, "Better Man," for the first time on stage, sharing a photo of the performance to Instagram afterwards.
"'The bravest thing I ever did was… run,'" she wrote. "Performing "Better Man" tonight for the first time, sending so much love and gratitude to @littlebigtown."
While there were no Swift Squaddies in sight, there were plenty of other celebrities among the thousands of fans packed into the performance, including John Legend and Chrissy Teigen, Lea Michele and Ruby Rose, who performed a DJ set to warm up the audience before Taylor took the stage.
ET caught up with Avengersstars Jeremy Renner and Chris Evans on the red carpet before the show where they revealed they'll be spending their Super Bowl Sunday watching the game from the comfort of the DirectTV suite -- but not betting on the game!
"Not on the Super Bowl," said Evans. "You've gotta keep that one pure."