Justin Bieber fans in Australia did finally get to see him perform ... from behind a glass barrier.
After an outdoor, three-song mini concert at Circular Quay was canceled by cops due to safety concerns for his crazy fans, the Biebs appeared in-studio for local TV show "Sunrise" instead -- and sang one song separated from his public by a glass wall.
Bieber tweeted after the gig "I'mbeyond grateful...that was incredible. Thank u for such an amazing warmwelcome Australia...I told you I wouldnt let you down. Thank U!"