Fan frenzy at Bieber pitch as star works the Australia's Got Talent crowd!

CANADIAN superstar Justin Bieber had the Australia's Got Talent tweens hysterically weeping as he busted some moves.

                 

Girls in the AGT moshpit went into meltdown, collectively heaving and almost rushing the stage in their frenzy.

Security certainly had their work cut out for them as the overwhelmed Beliebers cried out for their teen idol.

Even judge Kyle Sandilands' 20-year-old girlfriend, Imogen Eliza Anthony, couldn't help but join in, waiting eagerly in the front row for Bieber to hit the stage.

But the Canadian teen has seen and heard it all before and Seven insiders backstage described him as the ultimate professional.

With noise levels reaching fever pitch, Bieber, who had almost left the Docklands venue, decided to turn back to make sure his performance sounded spot-on.

The Baby singer told Seven officials he couldn't hear himself singing over the screaming teenagers, so wanted to review his two-song medley.

After giving it the thumbs-up the singer and his entourage slipped out, to more screaming fans throwing themselves on to his departing car