Brown picked up three awards at the show
R&B singer Chris Brown was the big winner at the American Music Awards (AMA) in Los Angeles, picking up three prizes including artist of the year.
"I would've gave it to Coldplay - I'm at a loss for words," a shocked Brown said of the night's biggest award.
The 19-year-old was also named favourite male artist in both the soul/R&B and pop/rock categories.
Artists Kanye West, Rihanna and Alicia Keys were all double winners at the awards, determined by a public vote.
It was West's first American Music Awards win, after failing to pick up any trophies after being nominated in 2004 and 2006.
"I'd like to thank everyone who accepted me trying to break new boundaries in music," he said after winning favourite male rap/hip-hop artist and favourite rap/hip-hop album for Graduation.
Highlights from American Music Awards
Rhianna was named favourite female artist in both the soul/R&B and pop/rock categories and Keys' album, As I Am, was the favourite pop/rock and soul/R&B album.
Coldplay, who had been nominated for four awards, went home empty-handed.
Annie Lennox was given the award of merit
Beyonce, Pussycat Dolls, Coldplay, Jonas Brothers and Miley Cyrus all performed at the ceremony.
As did former Eurythmics singer Annie Lennox, who won the award of merit.
"I never thought I would live to see the day that I could be 53-years-old standing on a stage," she said as she accepted the trophy from Justin Timberlake.
"It's been an incredible journey. Music: my friend, my accompaniment through life."
Other winners included American Idol finalist Chris Daughtry, who won favourite band in the rock/pop category, and Linkin Park who took home the prize for favourite alternative rock music act.
The country music awards went to Brad Paisley for favourite artist, 18-year-old Taylor Swift for favourite female act and Rascal Flatts for favourite band, duo or group.
Animated characters Alvin and the Chipmunks also picked up the award for favourite soundtrack album, beating the music from Mamma Mia! and Juno.
For the second year, winners were determined by online voting.
It used to be decided by a poll of 20,000 music buyers, but producers decided to make the event more inclusive in the wake of falling TV ratings.