Justin Bieber wins four American Music Awards
Teen star Justin Bieber dominated the American Music Awards winning four prizes from four nominations.
Bieber, 16, who beat Eminem, Usher, Katy Perry and Lady Gaga to artist of the year, also won best pop album, best pop male, and breakthrough artist.
He said he had "been singing Eminem since I was three and Usher is my mentor - so this is big".
Eminem led the field with five nods alongside country band Lady Antebellum. He won two awards as did Usher.
Eminem, 38 - who did not attend the ceremony at the Nokia Theater in Los Angeles - won best male hip-hop artist and the hip-hop album prize for Recovery.
Usher, 32, meanwhile, won best male R&B singer and the R&B album award for Raymond v Raymond while Lady Antebellum walked away with one award - for best country band.
British band Muse won the alternative rock prize.
Collecting his breakthrough artist award, Bieber - whose album My World 2.0 has sold almost 2 million copies in the US since its release in March - said: "I'm from the smallest town in the world of, like, 30,000 people.
"I never thought this was possible."
Bieber, who was brought up in Stratford, Ontario, now lives in the US.
Picking up his best pop male prize later in the evening, he thanked Michael Jackson, who last year won four posthumous gongs at the awards.
"Without Michael Jackson, none of us would be here," he said.
Other winners included best pop band the Black Eyed Peas - who performed new single The Time - and best country female Taylor Swift, who was last year's big winner with five gongs.
Swift, 20, performed her new single, Back to December, and incorporated OneRepublic hit Apologize.
Other performers on the night included 1990s boy bands New Kids on the Block and Backstreet Boys who sang together.
Meanwhile, Rihanna - winner of best R&B female - performed a medley of songs from album Loud.
A pregnant Pink performed Raise Your Glass, Kid Rock gave an acoustic performance of Times Like These and Katy Perry used pyrotechnics to play her latest single Firework.
In the absence of Lady Gaga, who did not turn up to pick up her best pop female prize, Kesha gave perhaps the most bizarre performance of the night.
She sported a motorcycle helmet with light beams for eyes as she sang her hit Take It Off.
She then stripped off to reveal a mirrored outfit and was joined by a gang of male dancers dressed like her - complete with fishnet stocking and blonde wigs.
Other winners on the night included Michael Buble, who won best contemporary artist, and Shakira who picked up the Latin music gong.