It is discovered and demonstrated that free ground Cr is singular in being the only 3d metal atom which develops dramatic orbital (anti-)collapse of its excited nd (3p to nd, n>or=3) orbitals. This finding is suspected to be a direct consequence of the well known fundamental irregularity in the filling of the 3d and 4s orbitals of the Cr ground-state configuration. It is also revealed that preliminary removing or excitation of the outermost 4s electron from the ground state of Cr conceals the orbital (anti-)collapse of the subsequent nd excited orbitals. All the results obtained are the first evidences for rather a delicate balance of the intra-potential of Cr for the whole nd states. The calculations are performed in the frame of the 'spin-polarized' Hartree-Fock approximation.