The transient combustion of a liquid fuel droplet which instantaneously reaches its thermodynamic critical state on introduction into a supercritical stagnant oxidizing environment was studied using second order reaction kinetics. The relevant conservation equations were solved numerically for a fuel-oxidizer system consisting of octane and oxygen, with the products of combustion and neutral nitrogen also being involved in the computation. Comparisons were made with previous flame sheet models with respect to burning time and flame zone location. Ignition delay was defined and computed. The distribution of the computed radial mass average velocity is presented and discussed.