Taylor Swift Brings Out Selena Gomez & Troye Sivan During Night 2 at the Rose Bowl: Watch

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Selena Gomez and Taylor Swift perform onstage during the Taylor Swift reputation Stadium Tour at the Rose Bowl on May 19, 2018 in Pasadena, Calif.

What's the best way for Taylor Swift to celebrate selling out two nights at the Rose Bowl? Performing with her best friend and favorite singer, of course.

Twenty-four hours after surprising Swifties with Shawn Mendes on night one of her Rose Bowl run, Swift brought out Selena Gomez and Troye Sivan on Saturday night (May 19). Swift and Gomez shared the stage for the "Delicate" singer's favorite Sel song, "Hands to Myself," while Sivan performed a rendition of his latest hit "My, My, My" with Taylor's help.

After singing "Hands to Myself," Gomez paid tribute to her bestie -- of almost 13 years, as she pointed out -- by thanking fans for supporting "the most beautiful, strong, independent woman I have ever met" as well as Swift herself for changing her life with their friendship.

"The reason why she has been one of my best friends is because this person has never ever judged a single decision I've made, she has always met me where I've been, she's encouraged me when I've had nothing to be encouraged about," Gomez told the crowd. "And I don't know if I would be as strong as I am if I didn't have you and your family because you've changed my life."

As for Sivan, Swift took to her Instagram story to declare that she is "super fan number one" of the Australian singer, sharing some fun videos from their pre-show prep. And while on stage, Swift took a minute to help Sivan reveal that his highly anticipated sophomore album, Bloom, will be coming out on Aug. 31. Needless to say, it was a big night for everyone involved.

Watch clips of Gomez and Sivan performing with Swift below.