Justin Bieber took the American Music Awards 2020 stage and belted out two of his biggest hits on Sunday, November 22, before being joined by Shawn Mendes.The Canadian crooner, 26, treated fans to a medley featuring “Lonely” and “Holy” to open the awards show before he and Mendes dueted on “Monster.”The “Yummy” singer was nominated for four awards at the 48th annual event.