Justin Bieber became a Hello on American Awards

America proved its Bieber Fever was strong: The teen singer dominated the American Music Awards on Sunday night. Bieber's wins included the show's top award, artist of the year. His mom joined him onstage as he collected the trophy, beating out Rihanna, Maroon 5, Katy Perry and Drake. "I wanted to thank you for always believing in me," Bieber said, looking to his mom. The 18-year-old also won the honor in 2010. He said it's "hard growing up with everyone watching me" and asked that people continue to believe in him. Bieber and Nicki Minaj performed together — and separately — at the AMAs, and were both multiple winners. But another collaboration was the night's most colorful performance: Korean rapper PSY and MC Hammer. Hammer joined the buzzed-about pop star for his viral hit "Gangnam Style." PSY rocked traditional "Hammer" pants as they danced to his jam and to Hammer's "Too Legit to Quit." Bieber won favorite pop/rock male artist in the first award handed out at Sunday's show and gave a shout-out to those who didn't think he would last on the music scene. "I want to say this is for all the haters who thought I was just here for one or two years. I feel like I'm going to be here for a very long time," he said. He also won favorite pop/rock album for his platinum-selling third album, "Believe." He gave a stripped down, acoustic performance of "As Long As You Love Me," then transitioned to the dance-heavy "Beauty and a Beat," where Minaj joined him onstage, grinding with the teen for a few seconds.