Justin Bieber Fast Times With Usain Bolt

11/29/2016 7:35 AM PST BY TMZ STAFF

Justin Bieber got down with the fastest man on Earth to celebrate a movie about the Olympian ... and he was anything but sorry to be partying with the champ.

Bieber was in London Monday night and showed up to an after-party following a screening of "I Am Bolt" -- a documentary about Usain Bolt's journey to the Rio Olympics.

Unclear if the Biebs saw the film itself, but he definitely raged with the man of the hour afterward.

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One Direction's Liam Payne was there for the screening and party too, but was reportedly on the opposite side of the room ... meaning he missed out on the Bolt/Bieber selfies.

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