LOS ANGELES (KTLA) -- Singer Chris Brown was nominated for six awards -- more than any other artist -- at Sunday's BET Awards ceremony, and took away four wins, including Best Male R&B Artist and Best Collaboration.

The awards come after Brown has came under fire for his attack on former girlfriend, singer Rihanna, over two years ago. He most recently smashed a dressing room window after an appearance on "Good Morning America," during which he was questioned about the incident involving Rihanna.

Brown has apologized for both incidents.

"I just appreciate every blessing that's been in front of me," Brown said during an acceptance speech at the awards show.

A mix-up between a computer tablet and a teleprompter caused an awkward moment during the show.

Tiffany Green, a fan from Flat Rock, Michigan, was chosen to announce the winner of the Coca-Cola Viewers Choice Award.

She was reading the name from a Sprint Evo tablet. Green first called Brown's name, but then squinted at the teleprompter before confidently announcing that Rihanna had won.

Stephen Hill, BET's programming president, took blame backstage for what he called "a human error," CNN reports.

Brown's name was correctly on the tablet in Green's hand, but the show producers put the wrong name -- Rihanna's -- on the teleprompter, Hill said.

The 21-year-old singer performed at the event, hosted by Kevin Hart. Lil Wayne, who trailed behind Brown with five nominations, and Beyonce, Alicia Keys, Jill Scott and Mary J. Blige also performed at the event. Nicky Minaj, Bruno Mars, Gladys Knight and Justin Bieber made appearances on stage.

Willow and Jaden Smith shared the Youngstars award. Other award recipients included Minaj, Kanye West, and Wiz Khalifa.

Patti Labelle received the 2011 Lifetime Achievement Award, and Steve Harvey received this year's Humanitarian Award.

The awards ceremony was broadcast live from the Shrine Auditorium and will be airing on BET from 8pm until 11pm EDT.

Brown's emotional tribute to Michael Jackson at last year's ceremony became a pivotal event in his career.