The discharge or arc tube chamber of a low-power high-pressure discharge lamp is, in one single step, sealed and shaped by mold or form-blowing by using pinch or press jaws (30, 31) which have concave hollows (34) formed therein to clearly define the shape of the discharge vessel, and hence of the discharge or arc tube chamber, to permit reproducible results with little variation between individual lamps to be made in a single manufacturing step. Additionally, an inclined ramp-like surface can be formed at the narrow sides (14) of the pinch seal extending towards the walls (11) of the discharge chamber (3) to thereby eliminate pockets beneath the electrodes. Preferably, the electrode shafts diverge with respect to the optical axis (A) of the lamp to increase the electrode spacing, and thus permit operation at a lower operating pressure, with respect to prior art lamps.