Driving non-photoresponsive transformations out of equilibrium with light requires transducing light energy into a different stimulus. Here, we demonstrate this using a dynamic-covalent network of four interconverting imines. In this system, photoirradiation drives a transimination reaction involving photoswitchable imines into a non-equilibrium steady state, altering the composition of both the photochromic imines and free amines. This shift in amine composition subsequently perturbs a coupled transimination reaction that does not directly absorb this wavelength of light. Notably, coupling these two reactions enhances the system’s response; the amines generated in each transimination facilitate the other, amplifying the overall departure from equilibrium beyond what is observed for the reactions in isolation. Operating entirely in solution, this light-fueled cascade provides a blueprint for designing dynamic-covalent systems that harness light energy to control non-photoresponsive transformations, expanding the scope and complexity of light-driven processes in systems chemistry.