The present disclosure describes apparatuses and techniques of fast transient response for switching power regulators. In some aspects, an output voltage of a switching regulator operating in a discontinuous mode is monitored via a comparator coupled directly to an output of the switching regulator. In response to the output voltage falling below a predefined threshold, a high-side switch is activated to provide current to a load connected to the output of the switching regulator. The switching regulator is then transitioned from the discontinuous mode of operation to a continuous mode of operation to control subsequent operation of the high-side switch. This can be effective to mitigate a drop in the output voltage of the switching regulator when an amount of current consumed by the load increases (e.g., a load step).