The teen idol dominated the American Music Awards on Sunday, winning four trophies to go with ear-piercing squeals from the girls at L.A.'s Nokia Theatre.
"I can't stop smiling," says Bieber, who won for pop/rock male, breakthrough artist, album of the year for My World 2.0 and artist of the year.
In becoming the youngest artist to win the top AMA honor, Bieber invited Usher to the stage, calling the R&B star "not only my mentor but my best friend and my big brother."
Usher picked up two awards – for male soul/R&B artist and for his album, Raymond v. Raymond. Eminem also was a double winner for male rap/hip-hop artist and for his album, Recovery.
Other winners included Lady Gaga for pop/rock female, The Black Eyed Peas for pop/rock group, Brad Paisley for male country artist, Taylor Swift for female country artist, Lady Antebellum for country group and Carrie Underwood for country album of the year for Play On.