The hypothetical Dark Matter (DM) has never been materially observed, measured or detected but is invoked to explain anomalous gravitational lensing and excess stellar and galaxy rotational velocities. We show that such DM effects are caused by large-scale enhancement of the spacetime metric due to the gravitational potential effects of the supermassive blackholes (SMBHs) at the centers of most galaxies. This SMBH model explains the magnitude of the DM effect relative to baryonic effects in galaxies, clusters and Universe expansion; the absence of any observed DM effect in diffuse galaxies as they have no SMBH; why in the Bullet Cluster the DM effect is coincident with the location of the visible galaxies and their SMBHs, and the intrinsic zero-pressure purely-gravitational interaction of the SMBH gravitational potential with baryonic matter.