Abstract: A formed, filled, and sealed flexible container is provided with an attached port assembly. The container is formed from film folded to define opposing sidewalls which are sealed to define a chamber for sterile fluid. A hollow, tubular port member is provided with a V-shaped saddle and is sealed to the bottom of the container. The film at the bottom of the container is received in the saddle. A unique shoulder is defined by the tubular port member. The film is sealed to the shoulder and to the saddle of the port member. A hollow penetrator element is slidably disposed within the port member and is movable between a retracted position and an advanced position to puncture the film whereby fluid can flow out of the container. Internal formations are provided to guide and to limit the movement of the penetrator element. The container film may be provided with a crease along the bottom of the container.