A power-based control system and method for an engine comprising a turbocharger involve obtaining a set of parameters that each affect exhaust gas energy and using the set of parameters to (i) determine a target mass flow into the engine and a target boost for the turbocharger to achieve a torque request, (ii) determine a target power for a compressor of the turbocharger to achieve the target engine mass flow and the target turbocharger boost, (iii) determine a target pressure ratio and a target mass exhaust flow for the turbine of the turbocharger to achieve a target turbine power equal to the target compressor power, and (iv) determine a target position of the wastegate valve to achieve the target turbine pressure ratio and mass exhaust flow, and commanding a wastegate valve to the target position.