Epidural Electrical Stimulation (EES) of the spinal cord is a promising therapy that has alleviated gait deficits in animal models and patients with Parkinson's disease (PD). Here, we hypothesised that closed-loop stimulation - targeted to specific phases of cortical oscillations - can refine the interaction of EES with pathological network states. For this, we tailored a real-time system that tracks a selected frequency and used it to deliver stimulation pulses timed to ECOG signals from M2 cortex. We tested the stimulation platform in the unilateral 6-OHDA PD rat model, that resulted in modulation of network activity dependent on precise time point of stimulation. Together, our results provide a new strategy for the design of closed-loop stimulation systems for future clinical translation.