The invention concerns a method for joining a metal component and a polymer component, and a structure comprising said components. In the method, an extrusion die plate with a through hole is placed between the metal component and the polymer component. A probe is rotated and plunged across the thickness of the metal component and eventually through said through hole of the extrusion die plate, thereby extruding a part of the metal component through said through hole of the extrusion die plate into the polymer component. The probe has a rotation axis having an offset to the centre of the through hole during the rotating and plunging action.