Ryan Dunn

By DAVID GARDNER

Oh what a night: Justin Bieber puckers up to Katy Perry backstage at the American Music Awards last night

At 26, she maybe a little older than this usual fans, but Katy Perry came down with a serious case of Bieber fever at the American Music Awards last night.

The pop star was among the first to congratulate Justin, 16, after he became the youngest ever winner of the coveted Favourite Artist crown.

The fresh-faced singer from Canada also won statuettes for favourite pop album, breakthrough artist and favourite male pop artist.

Katy, who performed her track Fireworks at the show, was spotted playfully puckered up to the teen star backstage.

More kisses and hugs! The singer, who was joined at the awards by her husband Russell Brand, couldn't hide her affection for the star

And she dived in for yet another kiss in the auditorium while her husband Russell Brand watched on.

Katy eventually managed to tear herself away from him and headed off to the Rolling Stones VIP do along with Kelly Osbourne, Mena Suvari and Ke$ha.

Justin didn't attend the late night after party, perhaps because of his tender age.
But his spirits were certainly high as he climbed on stage to collect one of his awards earlier in the night.

Ready for fun: Katy and Russell went on to the official Rolling Stone after party following the ceremony

‘I’m from the smallest town in the world of, like, 30,000 people,’ he told the star-studded crowd at the Nokia Theatre in Los Angeles. ‘I never thought this was possible.’

Bieber was discovered two years ago after posting his home-made pop videos on YouTube. They were seen by R&B star Usher, who helped his young protégé win a record contract.

Now the teenager is the hottest commodity in the music world. His album, ‘My World 2.0’, has sold almost two million copies since its release last year, thanks mainly to the devotion of his young female fans.

He is touring the UK next spring and recently sang one of his hits on X-Factor.

LBDs at the ready: Kelly Osbourne and Mena Suvari joined the crowd at the after party

Punk princesses: Ke$sha and Avril Lavigne looked ready for fun

'I can’t stop smiling, this is amazing,’ he said after his wins. ‘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.’

Bieber, who sang his single 'Pray' on the show, caused some confusion after picking up the pop artist prize, saying: ‘Without Michael Jackson none of us would be here.’

Afterwards, he laughed it off, saying: ‘You know, I said, 'Without Michael we wouldn't have been here,' but we would be here, but music wouldn't be the same.

‘I want to clarify that you'd still be born. Michael's not your dad or anything. You'd still be here. He's not your father.’

A touch of sparkle: Dancing With The Stars' former competitor Brandy and professional dancer Karina Smirnoff shimmered in sequins

R&B singer Usher admitted he broke down in tears of joy over Justin's victory.
The 32-year-old said: "The entire show was a success.

"The B man! To see Justin, having have received that award [Artist of the Year] before, it was like an out of body experience, I don't cry often, but I did!"
Usher added: "The first song that he ever did was 'Bigger' and that was kind of like the mantra, to do everything bigger.

"He had the talent, he could sing...I [knew I would] love to be apart of what he is to become and it is what it is."

Usher signed Bieber to his Raymond Braun Media Group in 2008 and helped him get a deal with Island Def Jam Music Group just after.