A new type of non-linear resonance is reported. It possesses an unusual counterintuitive feature, namely that: strong non-linear response to a weak periodic force can be obtained in the absence of exact resonance between frequency of the force and any eigenfrequency of the system. It is shown that the topology of phase trajectories differs substantially from the case of conventional non-linear resonance. The frequency of a driving force at which the transition between the conventional non-linear resonance and the zero-dispersion one takes place is found. Possible applications are discussed.