MOISTEN : DRENCH ::

To figure out a similar pair, we first need to understand the pair already present.

Moisten: Drench refers to the action of wetting with varying intensity, moisten is very low intensity, and drenching is very high intensity. 

So the relationship is one of a high-intensity word and a low-intensity word describing the same action. A prick is a light, shallow or small puncture, whereas a stab is a deep, forceful and violent thrust. 

Prick and stab are the best pair; both refer to piercing a surface with a sharp object.