JUSTIN BIEBER was BOOED when he took the stage last night for the first of four shows at London's 02 arena...because he was TWO HOURS LATE.
The show was supposed to start at 8:30, but he didn't get out there until 10:30. A lot of younger fans had to leave before the show even started. There's no word why it was delayed.
(--Justin's rep is denying this. He says Justin was only about half an hour late, and nobody booed.)