Two heartthrobs on one stage!

Justin Timberlake had a special surprise for his fans on Saturday at the iHeartRadio Music Festival in Las Vegas, Nevada. The 37-year-old singer invited 20-year-old rising star Shawn Mendes to join him to the delight of the audience.

"I’m a big fan of this young man. He’s one of the coolest cats I’ve met,” Timberlake said of Mendes. "He’s very talented, and he’s about to bless you. Please welcome, Shawn Mendes to the stage.”

Both musicians brought out their acoustic guitars to jam out to a slowed-down version of Timberlake’s hit, “What Goes Around… Comes Around.” 

The performance earned them massive cheers from the audience, and Mendes took to Instagram to share his appreciation. "Thank you @justintimberlake for being such an incredible guy,” he captioned a shot of himself with the fellow pop star. 

The pair also posed together backstage ahead of the performance, and looked very dapper. “About to bring this guy on stage…” Timberlake captioned the pic. 

Timberlake recently returned stateside for the next leg of his Man of the Woods tour after taking on Europe over the summer with wife Jessica Biel and son Silas by his side.