Taylor Swift had a jetset weekend. The singer performed at the KIIS Jingle Ball in Los Angeles on Saturday (Dec. 1) before jetting back to NYC, where she was photographed in Central Park with rumored new flame Harry Styles of One Direction. Talk about busy! Despite her hectic schedule, Swift delivered a spot on version of her newest anthem, 'I Knew You Were Trouble.'

Fan-filmed footage of Swift rocking the song, which she has done with increasing frequency lately, on the Nokia Theater stage has surfaced. Looking cute in high-waisted black hot shorts and a sparkly red top, Swift delivered the song to a crowd that was singing the lyrics right back to her -- and rather loudly. The singer looked festive and holiday-ready as she rocked out.

Swift even dropped to her knees at one point -- during the "trouble, trouble, trouble" part about three minutes into the clip -- with her hair flailing around her. This song certainly brings out the rock n' roll side of America's sweetheart. She also strutted around the stage while interacting with her band, too. This song gives her so much confidence.

We like when Swift gets sassy!