Taylor Swift and Gracie Abrams perform their song "Us" in Toronto

Taylor Swift's Eras Tour is winding down, and for her third show in Toronto, she surprised the crowd by bringing out one of her opening performers, Gracie Abrams, to sing their song "Us" with her.

It was the first time they had sung the song since it was nominated last week for a Grammy in the Best Pop Duo/Group Performance category. The only other time they have sung it together in public was in June, at Wembley Stadium in London.

Before they sang, Swift shared how the two grew closer as friends and how they wrote the song together after Abrams was nominated for Best New Artist at last year's Grammy Awards. "We had, like, eleventy-hundred Cosmos, went back to my house and just started writing a song. And the coolest thing ever has happened this week," she told the crowd at the Rogers Centre, referring to last week's nomination.

Swift said they got on a phone call right after finding out about the Grammy news. "It was just screeching; it wasn't even words. It was just feral screeching for the entire call, and we were so excited about that," she continued. "We wanted to figure out a way to say thank you to you, so we put together a little something." Then the pair performed their song and combined it with Swift's 1989 (Taylor's Version) single, "Out of the Woods."

The song served as the acoustic part of the surprise song set that Swift has included in her show throughout the tour. Once they had finished their song, she made her way over to the piano and sang a mash-up of "You're on Your Own, Kid" from her 2022 album, Midnights, and a song from Evermore called "Long Story Short."

Swift will now begin wrapping up her momentous, record-breaking global tour, with only six shows left on the schedule.