We have extended the previous fluctuation exchange approximation for the two-dimensional Hubbard model to a Fermi surface geometry approximating that of the YBa 2Cu 3O 7− y cuptrates. In spite of the poor nesting of this Fermi surface we obtain a broad commensurate peak in the spectral density of the dynamic spin susceptibility, Im χ s ( q, ω) , provided that the coupling is sufficiently large ( U/ t ≳ 7). The antiparamagnons soften and the quasiparticles exhibit marginal Fermi liquid behavior as the band filling n tends to half filling n = 1. The eigenvalue λ d for d x 2− y 2 pairing increases with U and n, or decreasing T; however, we have not reached the pairing instability where λ d = 1 (for example, λ d = 0.91 for U/ t = 6.8, n = 0.95, and T = 0.0224 t). In the second part we use a coupling J( q) which is peaked at Q . Then we obtain a commensurate peak and d x 2− y 2 wave superconductivity, for example, at U/ t = 3.7, n = 0.85, and T c = 0.039 t. Below T c, a gap and a peak at higher frequency develop rapidly in Im χ s ( Q, ω) , in qualitative agreement with neutron-scattering data. The density of states N( ω) is linear in ω which is consistent with the observed low-temperature variation of the penetration depth. In the photoemission intensity along the antinode of the gap the quasiparticle peak shifts to lower frequency and a dip develops as T decreases below T c. This behavior is in qualitative agreement with ARPES data obtained on Bi-2212.