Teen singer Justin Bieber won four prizes from four nominations at the American Music Awards.

The 16-year-old star scooped the prestigious Artist Of The Year award, beating off rivals Eminem, Katy Perry, Lady Gaga and Usher.

Other winners at the star-studded event included Usher, Muse, Black Eyed Peas, Taylor Swift, Rihanna and Lady Antebellum.

Justin Bieber said: “I’ve been singing Eminem since I was three and Usher is my mentor – so this is big.”

Bieber’s idols Eminem and Usher both came away with two awards.