The country star joined the band for "It's Only Rock 'N' Roll (But I Like It)," the title track to the band's 1974 album of the same name.

"I'm pretty sure tonight is going to be one of the greatest nights of my life! I'm singing with THE ROLLING STONES!!! Still can't believe it!," tweeted Underwood before the show.

Afterwards, she posted, "I just sang with the @RollingStones! Holy cow! I walked off stage and said, "What just happened?!" Still can't believe it! :)"