Taylor Swift has surprised her fans by performing a duet with her "best friend" Selena Gomez.
The duo shared the stage for the first time in two years on Saturday (19May18), at the 28-year-old's second night of her Reputation Stadium Tour at the Rose Bowl Stadium in Pasadena, California.
Selena sweetly paid tribute to her friend after they performed her hit Hands to Myself and told the crowd Taylor has always supported her unconditionally.
"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," the 25-year-old said. "But honestly thank you from the bottom of my heart for supporting someone that I know that is the most beautiful, strong, independent woman I've ever met. So, thank you for supporting my best friend."
Taylor posted videos from rehearsals with Selena on her Instagram Stories after the show on Saturday, which revealed the former Disney star's shock at the size of the gig she was about to perform at.
"Just about to do soundcheck, and we have a special guest on hand... oh, look who it is!" she said, as Selena peered over her shoulder. "We're gonna go to be singing Hands to Myself, which is absolutely iconic."
The Shake It Off hitmaker later posted a video showing Selena trying to rehearse her performance but appearing overwhelmed by the size of the Rose Bowl stage.
"To the person I could call at any time of day, who has been there no matter what... you absolutely KILLED IT tonight and everyone was so excited to see you. I love you, and 60,000 people at the Rose Bowl loved you too," Taylor wrote after the concert on Instagram, posting videos and snaps from their time on stage together.
Taylor had another surprise up her sleeve for her fans on Saturday as she brought out singer Troye Sivan too.
The 22-year-old wore a T-shirt from Taylor's tour merchandise as they performed his new single My My My!
Taylor also treated her fans to a duet with Shawn Mendes on Friday (18May18) at the Rose Bowl, with the pair performing his track There's Nothing Holdin' Me Back.