A self-opening closure includes a pouring sport, a screw cap and a self-opening cylinder, which is disposed inside the pouring spout and can be set rotating by the screw cap. The self-opening cylinder has three combined piercing and cutting elements with the interior having three molded elements, evenly distributed and extending toward the center of the cylinder, which have a nail shank and a nail head. The nail shank and the nail head of each element acts as a guide for one of the three cylinder wall segments located on the interior of the cap, concentrically to the axis of rotation of the cap. The screw cap is connected to a retaining element by at least two material bridges extending non-radially in relation thereto that are configured as predetermined breaking points. The retaining element engages with a flange on the pouring spout.