A lidded container includes a container having an open top defined by an annular rim; a lid having a central section and an outer rim attachable to the rim of the container; and an annular gasket between the rim and the lid. The annular rim of the lid includes an annular clamping section defined by spaced inner and outer walls for receiving the rim of the container in the space between the walls. The annular clamping section of the lid is integrally joined to the central section of the lid by an annular, elastically deformable juncture section effective to increase (a) the clamping action of the lid clamping section, and (b) the sealing action of the gasket, with an increase in pressure within the container.