Bradley Cooper -- Dashes, then Crashes into Door (PHOTO)

Bradley Cooper made a dash for the hippest restaurant in London Friday night, but misjudged the opening and slammed into the front door.

Bradley was trying to make his way inside Chiltern Firehouse ... one of the best and most popular restaurants in London.

It's unclear how it happened, but photogs say he hit his head hard on the front door -- apparently he had his head down as he tried running inside.