  We present a new realization of the resonant production of primordial black
holes as well as gravitational waves in a two-stage inflation model consisting
of a scalar field \phi with an axion-monodromy-like periodic structure in the
potential that governs the first stage and another field \chi with a
hilltop-like potential that dominates the second stage. The parametric
resonance seeded by the periodic structure at the first stage amplifies the
perturbations of both fields inside the Hubble radius. While the evolution of
the background trajectory experiences a turn as the oscillatory barrier height
increases, the amplified perturbations of \chi remain as they are and
contribute to the final curvature perturbation. It turns out that the
primordial power spectrum displays a significant resonant peak on small scales,
which can lead to an abundant production of primordial black holes.
Furthermore, gravitational waves are also generated from the resonantly
enhanced field perturbations during inflation, the amplitude of which may be
constrained by future gravitational wave interferometers.
