Justin Bieber walked away with the American Music Awards artist of the year trophy, becoming the youngest person in the history of the of the event to win the award. The Canadian heartthrob chose to share the spotlight with his "mentor, best friend and big brother" Usher, whom he invited onstage during his moment of glory.

"I really was embraced by a man named Usher Raymond," Bieber said. "It would be only right if I invited him up here to share it with me. "

Bieber also captured two more trophies at the American Music Awards on Sunday, besting Eminem and Usher for favorite pop/rock male. The achievement of topping two multiplatinum veterans to win the award was not lost on the 16-year-old heartthrob, who praised both artists as he picked up the pop/rock award.

"I can't stop smiling; this is amazing. Truly I don't know how this is possible because I've been singing Eminem since I was three and Usher is my mentor. So this is big," said Bieber, who also won the show's breakthrough artist award.

Usher didn't walk away empty handed, though. The R&B star also captured early honors at the American Music Awards, beating out Alicia Keys and Sade for R&B/Soul album of the year. He later won the award for R&B/ Soul male later in the show.

"All of my team back in New York City, I'm bringing this home for you," the leather-clad crooner said as he held his trophy high.

Black Eyed Peas won best pop/rock band, duo or group. While they didn't give a noteworthy speech, frontman will.i.am wore a memorable outfit: A hat and a necklace made out of what appeared to be Legos. The band gave a levitating performance, singing from boxes atop the stage during part of their performance of their new single, "The Time."

"This is amazing!" said an exuberant Rihanna, who danced onstage to receive her award - favorite soul/R&B female. She ended her speech by yelling, "Wassup! Thank you!"

Rihanna, with her hair dyed a ruby red, gave the show a colorful and sexy start, performing a medley of songs from her just released album "Loud," including the No. 1 hit "What's My Name," wearing a bustier and what seemed like a scarf wrapped around her backside.

But some of the prime-time performances were given to acts who weren't nominated, but had albums to promote. Diddy's latest incarnation with the group Diddy-Dirty Money sang material from their upcoming album, while Kid Rock gave a stirring, acoustic performance of "Times Like These," his song lifting up his hometown of Detroit during its recent economic struggles, from his new CD, "Born Free."

Taylor Swift, last year's artist of the year, took home favorite country female. Sporting sleek blonde hair instead of her usual cascading curls, Swift said simply: "I just want to thank the fans."

Swift was due to perform later in the evening, along with Bon Jovi, a pregnant Pink and more.

A cold Los Angeles night didn't stop the stars from showing a little skin as they arrived for the awards at the Nokia Theatre. Miley Cyrus walked the red carpet wearing a strapless dress with a flowing train. Avril Lavigne rocked in a mini animal-print dress.

John Legend was more covered up than the ladies, but even he remarked on the cold and windy conditions. Still, he said he expected a "pop music explosion" during the show.

Eminem and Lady Antebellum were both up for a show-topping five awards apiece. Other major nominees include Ke$ha and Katy Perry.

Entertainment Writer Derrik L. Lang contributed to this report.