Bieber fever hits new heights as the Canadian star said goodbye for now to his Australian fans at an outdoor concert at Circular Quay.
Bieber did what security and police could not during Wednesday morning's Sunrise performance - persuade thousands of teenage fans to step back for their own safety.
Presenter David Koch did his best to calm the crowd after several distressed audience members were carried out by staff, but it required Bieber to intervene before they actually listened.
'Take a step back, everyone just take one step back. There we go,' Bieber said as the crowd duly followed.
Bieber fever' returned to Circular Quay via a chorus of girlie screams two years after a similar concert for the Seven Network was cancelled due to overcrowding.
While the event was ticketed this time, hundreds gathered on surrounding streets and balconies to catch a glimpse, while commuters danced on passing ferries.
As part of his final stop promoting the Believe album, Bieber performed singles Boyfriend and All Around The World and reserved a medley of songs for the gathered fans.
The 18-year-old reiterated his plans for live shows as part of a world tour in 2013 and promised to stay in touch with his Australian fans until the next visit.
'They spend all the time you know on the internet with me so I spend all my time on the internet with them,' he said.
'It's important to me... to just stay connected with them because they were there since the beginning.'
For many, the outdoor concert was a first chance to see the Canadian heartthrob since he jetted into Sydney on Monday night.
The true Beliebers camped overnight to get prize position, while the screams, tears and even some vomiting during the show proved the scale of his popularity.
'For me personally Justin has made me believe in my dreams,' said Natasha Perrone, 18, from Melbourne.
'I have a tattoo saying never say never' in Italian which was inspired by him.'
John Retford brought his 11-year-old daughter from their home in Albury, NSW, knowing little about Bieber other than the posters on her bedroom wall.
'I'm glad I came now because I know a lot more about him. He seems like a good kid.'