The invention relates to a high-pressure gas discharge lamp (8) for a lighting device, in particular for a headlight unit of a motor vehicle, with an electronic ignition system (9) that is arranged inside a lamp cap housing (1, 2) that comprises an upper part (1) and a cover (2), wherein said upper part (1) is provided with an opening (1.1) within which a high-voltage connection (4) between the high-pressure gas discharge lamp (8) and the electronic ignition system (9) is present, the cover (2) projects into said opening (1.1) and closes off this opening (1.1) in an insulating manner, and the mutually facing surfaces of the upper part (1) and the cover (2) form a labyrinth (3) that is interrupted by an insulating element (5).