With three hit singles and more than two million copies sold of her new album, 'Red,' since its release in late October, Taylor Swift is having a moment -- and she helped celebrate it by bringing her latest radio-dominating smash, 'I Knew You Were Trouble,' to the annual Jingle Ball Concert in Los Angeles on Saturday (Dec. 1).

Part of the show's newly expanded two-night lineup, Swift played this year's Jingle Ball alongside such fellow Saturday night performers as Ellie Goulding, Ne-Yo, and OneRepublic; tonight, the crowd will be treated to sets by acts including Justin Bieber, Kesha, the Wanted, and (of course) 'Gangnam Style' performer Psy.

But for the few minutes captured in this fan-shot footage, the stage was all Swift's. Prowling the risers in a glittery red top and a pair of mom-waisted couture shorts, she commiserated with her screaming fans, leading off the song by talking about what a drag it is when some guy walks in the room and as soon as you see him, you know he's... well, you can probably figure out the rest. See the whole thing for yourself in the video, embedded below.

Watch Taylor Swift Perform 'I Knew You Were Trouble' Live at the KIIS-FM Jingle Ball