The multireference generalized Van Vleck second-order perturbation theory (GVVPT2) method is used to describe full potential energy curves (PECs) of low-lying states of second-row transition metal dimers Y-2 and Tc-2, with scalar relativity included via the spin-free exact two-component (sf-X2C) Hamiltonian. Chemically motivated incomplete model spaces, of the style previously shown to describe complicated first-row transition metal diatoms well, were used and again shown to be effective. The studied states include the previously uncharacterized 2(1)Sigma(+)(g) and 3(1)Sigma(+)(g) PECs of Y-2. These states, together with 1(1)Sigma(+)(g), are relevant to g discussion of controversial results in the literature that suggest dissociation asymptotes that violate the noncrossing rule. The ground state of Y-2 was found to be X-5 Sigma(-)(u) (similar to Sc-2) with bond length R-e = 2.80 angstrom, binding energy D-e = 3.12 eV, and harmonic frequency omega(e) = 287.2 cm(-1), whereas the lowest 1(1)Sigma(+)(g) state of Y2 was found to lie 0.67 eV above the quintet ground state and had spectroscopic constants R-e = 3.21 angstrom, D-e = 0.91 eV, and omega(e) = 140.0 cm(-1). Calculations performed on Tc-2 include study of the previously uncharacterized relatively low-lying 1(5)Sigma(+)(g) and 1(9)Sigma(+)(g) states (i.e., 0.70 and 1.84 eV above 1(1)Sigma(+)(g), respectively). The ground state of Tc-2 was found to be X-3 Sigma(-)(g) with Re = 2.13 angstrom, D-e = 3.50 eV, and omega(e) = 336.6 cm(-1) (for the most stable isotope, Tc-98) whereas the lowest (1)Sigma(+)(g) state, generally accepted to be the ground state symmetry for isovalent Mn-2 and Re-2, was found to lie 0.47 eV above the X-3 Sigma(-)(g) state of Tc-2. The results broaden the range of demonstrated applicability of the GVVPT2 method.