A screwless quick connection system for connecting a lead connector to a generator of an active implantable medical device is shown and described. The connector head includes a housing receiving a plug of a lead connector. A mechanism for locking the plug into the housing is provided by a U-folded leaf spring. Each branch of the U is provided with a respective hole sized so that the plug passes through the holes on both branches when it is inserted into the housing. The blade is deformable between a free state, in the absence of plug, and a deformed state, with the plug inserted therein. In the free state, both holes are misaligned, while in the deformed state they are aligned. In this way, an edge of both holes exerts by reaction a radial stress force against the smooth outer surface of the plug inserted therein.