Jimmy Fallon Is a Rockstar During Performance at Jonas Brothers Show

Jimmy Fallon may just be the Jonas Brothers' brightest opening act.

The Tonight Show host served as a surprise special guest during the band's Aug. 13 show at Yankee Stadium in New York City. For the second sold-out show that kicked off their tour, the comedian took to the stage to belt out The Killers' song, "Mr. Brightside."

And not only did he showcase some of his best moves, but as seen in videos shared to social media, the crowd was more than happy to sing along during the electric performance.

Shortly after his solo spot was over, Jimmy shared a shoutout to the moment, writing on Twitter, "Huge thanks to @jonasbrothers for giving me the surprise guest spot on 'The Tour' tour. And thank you to @yankeestadium for turning it into the world's biggest karaoke party. This is one of those nights I will never forget."

Concertgoers also reacted to his performance on Twitter, with one person declaring, "I'm pretty sure @jimmyfallon is the fourth Jonas brother."

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