File under: The gang that Couldn't Shoot Straight.
The bottle that split open the head of Chris Brown's GIGANTIC bodyguard Wednesday night was thrown by a member of Team Breezy ... TMZ has learned.
Multiple witnesses say ... Brown's hired muscle, Big Pat, was standing in front of Chris when the bottles started flying. We're told Big Pat turned towards Chris ... when someone in Brown's own entourage fired a bottle intended for Drake's party, but missed ... bad.
Instead, the bottle connected with Big Pat's face at extremely close range ... and opened a giant bloody gash on his forehead. Pat ended up suffering the worst injuries of anyone in the club -- ironically from his own posse.
Pat received emergency medical treatment for the wound -- but he appeared fine the next day.