Classic origin of mesoscopic critical and boyle's singularities simulated by fluctuational potential We have used the developed recently methodology of the congruent vapor-liquid (CVL) diagram for prediction, in particular, of the entire vapor-liquid equilibrium (VLE) diagram in the test-fluid argon. The former is based on the proposed earlier principle of the global fluid asymmetry (GFA) which rejects the conventional concept of a unified fluid equation of state (EOS) in both sub-and supercritical regions. In contrast to the traditional VLE-locus applicable in the restricted (subcritical) range between critical (c T) and triple (t T) temperatures, the CVL-locus spans the much more wide ranges of fluid states located between the generalized Boyle's (B) points (0, FT B T ρ → ], (0, FT B T → ρ ] predicted by FT-model of fluctuational thermodynamics. The new shape, location and the opposite sign of curvature for the boundary of metastable liquid which does not pass over CP (critical point) have been revealed in the global fluid (f) temperature range (0, FT B T) including its supercritical segment. The classical GFA-origin of the asymptotic criticality is unambiguously established without any appeals to the non-classical scaling phenomenology but in accordance with its main findings, at least, in the regions of stable and metastable liquid. Since the fundamental concept of a homogeneous equilibrium Gibbsian phase achieves the limit of its applicability in the simulated discrete N,V-systems of the Lennard-Jones' particles, their metastable, at best, states are highlyprobable in the conventional scales of VLE-simulation.