Keith Urban and Carrie Underwood had something very special planned for the audience at the 2020 Country Radio Seminar in Nashville this week. The two superstars reunited to perform "The Fighter," their smash hit from 2017.

The unexpected moment came during Urban's performance at the Team UMG luncheon at the historic Ryman Auditorium in downtown Nashville on Thursday afternoon (Feb. 20). Urban first treated the invitation-only crowd of music business insiders, journalists and radio programmers who had traveled to Nashville for the annual three-day conference to a new song titled "God Whispered Your Name," and then he invited Underwood — who had performed "Spinning Bottles" earlier — to join him for on impromptu reunion, causing her to joke, "No soundcheck on this one, guys."

See their performance of "The Fighter" in the live video below:

Urban co-wrote "The Fighter" with the late songwriter and producer Busbee. The song appeared on Urban's 2017 Ripcord album, and it reached No. 2 when it was released as the fifth and final single from that project.

Urban and Underwood's unexpected duet performance was one of the highlights of the Team UMG luncheon, which is one of the most important events at CRS each year. The yearly conference brings together artists, managers, publicists and country radio for three days of performances, interviews, showcases, lectures and more, which helps set the agenda for the country music industry near the beginning of each year.

In addition to Urban's set, Sam Hunt was a highlight of the UMG event, performing a new song titled "2016" from his forthcoming sophomore album, Southside. Mickey Guyton, Jon Pardi, Luke Bryan and more also performed at the Universal Music Group event.

Keith Urban and Nicole Kidman's Home Threatened by Wildfires: 

See Keith and Nicole at the 2020 Golden Globe Awards: