Fans who attended the Garth Brooks and Trisha Yearwood concert in Chicago on Friday night (Sept. 5) got a huge surprise. Kelly Clarkson came out onstage to join Yearwood on their newly-released duet, 'PrizeFighter.'

“You’ve got this cool new song coming out. It’s with you and Kelly Clarkson,” Brooks said to his wife. As the crowd cheered, Brooks then said, “Hey! I’m going to be Kelly Clarkson tonight! I can sing better than Kelly Clarkson."

With that, Clarkson herself came out to join Yearwood for the powerful track, which is the title song of Trisha's upcoming new album for Sony/RCA Nashville. It was Clarkson's first public live performance since giving birth to her daughter, River Rose Blackstock, in June.

The show was also River's first-ever concert. Her excited mom tweeted about the experience afterward.

The show marked the second night of Brooks' massive comeback tour, which will encompass 10 shows in Chicago before moving on to a run of seven dates in Atlanta. Brooks is announcing the cities individually. Keep up with all of the upcoming dates here.

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