  We calculate the D-instanton corrections (with all D-instanton numbers) to
the quantum moduli space metric of a single matter hypermultiplet with toric
isometry, in the effective N=2 supergravity arising in type-IIA superstrings
compactified on a Calabi-Yau (CY) threefold of Hodge number h_{2,1}=1. The
non-perturbative quaternionic hypermultiplet metric is derived by resolution of
a complex orbifold singularity, thus generalizing the known (Ooguri-Vafa)
solution in flat spacetime to N=2 supergravity.
