Rihanna a monster winner at first-ever iHeartRadio Music Awards

Rihanna was the toast of the inaugural iHeartRadio Music Awards in Los Angeles on Thursday (01May14), despite arriving late and missing out on accepting the new prizegiving's first ever trophy.

The Umbrella singer found herself stuck in rush-hour traffic and wasn't even at the Shrine Auditorium when she won the night's Hip Hop/R&B Song of the Year for Pour it Up.

She arrived shortly afterward and was present to pick up her awards for Best Fan Army, Artist of the Year and Song of the Year (Stay).

Sporting a gothic look with blue lipstick, a black lace dress, jewelled crucifixes and a new Tank Girl-style hairdo, Rihanna accepted the latter trophy by thanking radio producers for playing the ballad, stating, "This record would never have been this big if it wasn't for you."

And accepting her Artist of the Year honor at the end of the night, she added, "Shout out to everybody who has ever worked on my project. I know I'm a pain in the a** - but it's worth it!"

It was also a huge night for Pharrell Williams, who picked up the first-ever iHeartRadio Innovator Award.

Presenter Gwen Stefani called her pal "the coolest guy ever", before a series of tributes from stars like Lady Gaga, Usher, Beyonce, Shakira, Oprah Winfrey, and Rita Ora flashed up on video screens.

The man of the hour then performed a hits medley, including Blurred Lines, Get Lucky and Happy.

Accepting his Innovator Award, the singer/songwriter/producer thanked his wife Helen Lasichanh and son Rocket and added, "I never dreamt in a million years that I'd be standing here as an artist... All I did was write the songs and you guys (fans) did all the heavy lifting, all the hard work, all those millions of views on YouTube... Thank you guys so much for lifting me so high."

Pitbull opened the show by performing Wild Wild Love and Timber without his duet partner Kesha, who has yet to perform for the first time following a stint in rehab earlier this year (14). The track won the couple the Best Collaboration trophy.

Performance highlights also included sets from Bastille, Ariana Grande, Shakira, Kendrick Lamar and 30 Seconds to Mars, who played City of Angels as frontman Jared Leto's accompanying short film featuring stars like Kanye West, Selena Gomez and Lindsay Lohan talking about their love of Los Angeles flashed up on video screens on either side of the stage.

But the night's talking point came when Usher showed off his Michael Jackson moves as he danced along to the King of Pop's new single Love Never Felt So Good, which debuted during the ceremony.

As images of the late Thriller star appeared on video screens on the stage and throughout the audience, Usher and a gang of dancers performed the pop superstar's moon walk and other signature moves.

The iHeartRadio Music Awards telecast also featured a series of pre-taped anecdotes about L.A. from the likes of Chris Martin, John Legend, Steven Tyler, Adam Lambert, Lady Gaga, Rita Ora, Macklemore & Ryan Lewis and Iggy Azalea.

More than 60 million radio listeners voted for the awards.