Abstract: A spark plug includes a sparking electrode with a firing tip and a ground electrode. The ground electrode includes a toroidal member, having a convex outer surface, coupled to a support portion of a sleeve of the ground electrode. The toroidal member forms an annular curve disposed generally transverse to and having a radial center coinciding with a central axis of the insulator body, whereby each differential segment of the toroidal member radially thereabout is generally equidistant to the firing tip. The toroidal member is a closest portion of the ground electrode relative to the firing tip. At least a portion of the outer surface of the toroidal member opposing the firing tip has a radius of curvature of about that of the firing tip for providing a spark path of least from the firing tip to a point of contact on the opposing surface defined by the toroidal member.