Carrie Underwood and Sam Hunt were both in London last week for performances at the Country to Country Music Festival, and it was too perfect of an opportunity not to sing together. During Underwood's set, she brought out Hunt to sing with her on her song "Heartbeat," on which he provides backing vocals.

Singing the first verse on her own dressed in a yellow sequined dress and knee-high black boots, a big smile appears on Underwood's face as she introduces the "Make You Miss Me" singer to the London audience at C2C.

"Ladies and gentleman, Sam Hunt!"

Hunt takes the stage to screams as he sings the second verse of the song, dressed in black jeans and a white hoodie. All smiles, the remainder of the performance finds him singing harmonies on the chorus with Underwood.

Underwood and Hunt first performed the song together at the Grammy Awards last month. That rendition included a mashup of Underwood's "Heartbeat" and Hunt's "Take Your Time." More recently, "Heartbeat" went to No. 1 on the country charts, giving Underwood her 23rd No. 1 hit and her 13th career No. 1 as a songwriter. She wrote "Heartbeat" with Zach Crowell and Ashley Gorley.

The "Smoke Break" star wrapped up the international dates of her Storyteller Tour this past weekend. Her three sold-out dates overseas included performances at Glasgow’s Clyde Auditorium, London’s O2 Arena and Dublin’s 3 Arena. She also played for the first time in Stockholm, Sweden and Oslo, Norway recently. Each of the five concert dates were part of the C2C Festival.

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