A source close to the situation told E! News the 19-year-old star and his entourage were kicked out of London's Cirque du Soir after a confrontation with club security.
The incident went down quickly and the "Beauty and a Beat" singer headed straight back to his hotel afterward, the source added.
E! also reported that Justin's new rumored flame, singer Ella-Paige Roberts Clarke, was in attendance.
Bieber's reps have yet to comment.
Birthday boy Justin Bieber started the evening tweeting, "Big night ahead," and ended it with "Worst birthday." What happened?!