Selena Gomez joined best friend Taylor Swift onstage at Madison Square Garden Tuesday night for their first duet together.

Swift, 21, invited Gomez to join her at the iconic New York venue as the country darling wrapped up her 98-show “Speak Now World Tour.”

Gomez, 19, serenaded the crowd with her teen anthem “Who Says.”

“Performing at Madison Square Garden with my best friend was a highlight,” Gomez tweeted to fans.

Swift also invited James Taylor to come onstage for a two-song jam session that included Taylor’s “Fire and Rain” and Swift’s “Fifteen.”

Following the final performance, Swift posted a message on Twitter that said she has “so much to be thankful for this year.”

“I’m leaving New York, replaying this tour in my mind. I love you all so much,” she added.