HunterGirl — a Top 3 finalist on Season 20’s American Idol who scored one of the highly sought after Platinum Tickets — hit the stage for a once-in-a-lifetime duet with her coach, Luke Bryan, on Sunday night (May 22).

The two artists traded vocals on a soaring cover of Randy Travis’ “I Told You So,” as part of the three-hour American Idol Season 20 finale, which aired live coast-to-coast beginning at 8PM ET on ABC.

The classic country song was first recorded for Travis’ 1983 album Live at the Nashville Palace and later added to his 1987 album, Always & Forever. The popular ballad has also been covered by country superstar Carrie Underwood in the past, then re-released as a duet with Travis.

Onstage, HunterGirl and Bryan nailed the smash hit with surprising chemistry. Bryan, looking dapper in all black, put his signature country vocals on the first verse before HunterGirl — dressed in a sparkling black floor-length gown — wowed with her powerhouse voice on the second verse.

The two then joined their vocals together in stunning harmony, ultimately giving the standing-room audience chills.

This isn’t the first time two singers revived “I Told You So” for American Idol. Underwood and Travis performed the classic country ballad on the show in 2009. Lauren Alaina and Scotty McCreery also covered the duet during the Season 10 Top 11 results show.

Bryan also wasn’t the only Idol judge to step outside of his seat on the judging panel and take the spotlight as part of the Season 20 finale on Sunday. His fellow coaches, Lionel Richie and Katy Perry, also delivered special performances with some of the standout contestants. Perry performed twice, once to sing “Firework” with Top 3 finalist Leah Marlene and later to collaborate on “Where We Started” with Thomas Rhett. Richie, meanwhile, took the stage with the Top 10 at the top of the telecast.

Before launching into her duet performance with Bryan, HunterGirl brought the emotion with her original debut song entitled “Red Bird,” which she officially released as a single on Friday (May 13).

“My farm, where my house is, and where my wife and family are, we named our farm Redbird Farm for that very reason,” Bryan, who named his farm in honor of his sister Kelly, who unexpectedly died in 2007, said through tears. “So we are not doing well up here right now. Lord, more tissues, please. Beautiful song. I mean, that’s how you write one. You take an experience and you turn it into a song. Those are the ones that stick. Great job on that.”

14 'American Idol' Singers Who Secretly Hooked Up — Or Did They?

At least two couples who met through American Idol got married, while one more could be headed in that direction. Not all American Idol hookups have a happy ending, however. Here are seven of the most talked about meet-ups, plus the real scoop on how serious things got.

More From KIKN-FM / Kickin' Country 99.1/100.5