For her final show of the American leg of the 2013 Red Tour -- and the third night of a sold-out trio of concerts at the Bridgestone Arena in Nashville -- Taylor Swift wanted 'Crazy,' and she got it.

The star invited Hunter Hayes, who began as an opening act on her Speak Now Tour, onstage for a joint performance of his smash hit 'I Want Crazy' for the Nashville faithful.

Swift and Hayes, undeniably two of the hottest acts in country music under the age of 25, riled up the crowd with their rousing rendition of the song and their youthful energy. The two jumped up and down as if the stage was a giant trampoline.

While Hayes knuckled down on his guitar, Swift commanded the crowd of more than 14,000 to jump around with them during the final part of the song -- and they obliged. The ground likely shook in Nashville for those few minutes.

It was a special way for Swift to end the domestic leg of her hugely successful tour. The guest spot also says a lot about the mega talent that is Hayes. He went from opening for Swift to helping her close out a trek that was filled with high-profile cameos, like Friday's performance with Luke Bryan and Saturday's with Rascal Flatts.

The two superstars high-fived each other before wrapping their duet. They done good and they knew it.

Swift will enjoy a short break and then head overseas for the Australian and New Zealand legs of the Red Tour.