Shawn Mendes Performs 'Mercy' & 'In Your Atmosphere' Mash-Up With John Mayer (Video)

Shawn Mendes got to perform with one of his idols this week.

The 18-year-old singer joined John Mayer on stage during the latter’s concert on Monday night (April 3) in Toronto, Canada.

PHOTOS: Check out the latest pics of Shawn Mendes

The duo sang a mashup of Shawn‘s hit “Mercy” and John‘s classic, “In Your Atmosphere.”

“The dynamite @shawnmendes joined me in Toronto tonight perform a “Mercy”/”In Your Atmosphere” mashup and it was over the top good. #thesearchforeverything #shawnmendes #bringingbacktheworddynamite,” John later wrote on Instagram.

“Damn. John Mayer is the best. My job is the best. U guys are the best. What an insane night,” Shawn tweeted.

Watch Shawn and John‘s duet below!