Watch Justin Timberlake Surprise Crowd with 'Friends in Low Places,' Featuring Garth Brooks

"Something don't feel right," he said before welcoming the legend onstage.

— -- It was the surprise of a lifetime.

A Nashville, Tennessee, crowd turned out Friday to see a Justin Timberlake show when the singer decided to bring country royalty to the stage, namely, Garth Brooks.

"I saw an ENTERTAINER tonight! @justintimberlake #Justinrcredible," Brooks posted on Instagram, along with a video of the two singing Brooks' famed 1990 hit "Friends in Low Places.”

In the video, posted in its entirety on YouTube, Timberlake, 33, starts singing the song first, the crowd joins in next, then Brooks takes the stage and the crowd goes nuts.

"Hold on," Timberlake says after the second verse, before welcoming the legend onstage. "Something don't feel right."