WATCH: Shawn Mendes Performs With James Bay, Jared Leto

Canada’s Shawn Mendes performed in front of thousands of music lovers Sunday at The Biggest Weekend in Swansea, Wales – and he shared the stage with James Bay and Jared Leto.

Mendes sang tracks from his just-released third album and was joined by Bay for a performance of his 2016 song “Mercy.” (In March 2015, Mendes tweeted: “James Bay is great.”)

The 19-year-old Ontario native returned to the stage during a set by Thirty Seconds to Mars, after frontman Leto told the crowd he was bringing out someone “very, very talented and extremely good looking.”

MORE: Watch Big Acts Perform On The Biggest Weekend

Mendes played guitar on “Rescue Me,” a track from Thirty Seconds to Mars’ new album America.

“Thx again for joining us on stage,” Leto tweeted after the show.