The Heathens hitmakers thanked their fans, stating, "You guys changed our lives".
Bruno Mars kicked off the ceremony with a high-energy performance of his new song 24k Magic and he was followed by One Direction star Niall Horan in his debut as a solo artist.
Niall became the first existing member of the boy band to release a solo single when This Town came out in September (16). He performed the song onstage at the Los Angeles ceremony.
Meanwhile, Gigi Hadid was also making her debut as a co-host, and showed off her comedy skills by impersonating America's new First Lady, Melania Trump. Gigi was hosting with funnyman Jay Pharoah.
Drake leads all 2016 AMA nominees with a record breaking 13 nods, while Rihanna has seven and Adele and Justin Bieber have five apiece.
As well as Horan and Mars, performers include Sting, Lady Gaga and Ariana Grande and Nicki Minaj.