Taylor Swift has shared the stage with T.I., Nicki Minaj, Usher, and B.o.B, just to name a few. On Saturday, America’s sweetheart capped off her four sold-out shows at L.A.’s Staples Center by bringing out Jennifer Lopez. The crowd went wild when J.Lo emerged to perform her 2002 hit “Jenny From the Block” with some help from Swift.

“When I was a little girl, you know you have that favorite song that you just would play over and over and over again in your room, just blast it in your room—and you’d sing in front of your mirror into a hair brush… Los Angeles, this is my hair brush song,” she said before J.Lo hit the stage.

She later tweeted about the surreal moment. “Sang Jenny From the Block with @JLo tonight at Staples Center. STILL FANGIRLING OUT ABOUT IT,” said Taylor, to which J.Lo responded, “thank you for inviting my family to be a part of yours!!!”

Watch T. Swift and J.Lo team up for the special set.