Justin Bieber's celebrity friends let him win a dance-off at his birthday party on Friday (02.03.12).

The 'Baby' hitmaker celebrated turning 18 with a huge bash thrown by manager Scooter Braun and mother Patti Mallette at the Beverly Wilshire Hotel and pals including Jaden and Willow Smith, Cody Simpson and Ashley Tisdale ensured he enjoyed the festivities by making sure he won the friendly competition.

Kim Kardashian and Mike Tyson were among the guests at Justin Bieber's surprise birthday party on Friday (02.03.12).

The 'Baby' hitmaker turned 18 on Thursday (01.03.12) and celebrated reaching the milestone age at a bash thrown by his manager Scooter Braun and mother Patti Mallette at the Beverly Wilshire Hotel, where guests also included his girlfriend Selena Gomez - who jetted in from Florida, where she has been filming 'Spring Breakers', for the occasion - Kylie and Kendall Jenner and Ashley Tisdale.

Ashley Tisdale is reportedly dating Taylor Swift's ex-boyfriend.

Boys Like Girls lead singer Martin Johnson spent New Year's Eve (31.12.11) in New York City with 'High School Musical' star Ashley before the pair flew back to Los Angeles together and sources close to the former bad boy say he has "turned his life around" since Taylor's team put an end to their fledgling relationship.

Ashley Tisdale has split from her boyfriend.

The 'High School Musical' star and music video director Scott Speer recently called time on their two year relationship after it "ran its course".