Abstract: A process and apparatus for combustion of fuel which results in reduction of nitrogen oxides and carbon monoxides emissions. Fuel and primary air are preferably premixed and introduced into a combustion chamber. Secondary air is introduced through a plurality of secondary air ports which are positioned about a venturi nozzle or flame holder disk mounted with respect to a combustion chamber wall. The secondary air flowing through the secondary air ports forms relatively high velocity and momentum secondary air jets that promote rapid mixing of the fuel and primary air mixture into the secondary air flow, such that a combustion flame is established at a periphery of the secondary air jets.