The present disclosure provides systems and methods wherein power production can be achieved with combustion of a fuel utilizing flameless combustion. A fuel may be combusted in a combustor/turbine in a substantially flameless operation to produce a combustion product stream that can be expanded for power generation. After expansion, the output stream can be treated to generate a recycle CO2 stream into which an oxidant can be input. The recycle CO2 stream including the oxidant can be injected into the combustor/turbine to effect combustion in a substantially flameless state. Various control schemes can be implemented to automatically control the concentration of oxygen present in the recycle CO2 stream that is injected into the combustor/turbine in order to achieve and/or maintain substantially flameless combustion.