The only thing I find myself doing when against a cleric is to simply keep kiting and poison/bleed him/her from time to time. But that's an inefficient way to use sp since they can easily heal themselves with much less cost to their sp pool. So in cases of 1v1 I avoid clerics altogether, but there is one occasion where a cleric several levels higher was killed by my skill spams. Also fighters are rather easy to kite to death without clerics supporting them, unless they want to go ahead and waste their dear pots.
P.s. does anyone know how DEX factor into added effects (bleed/poison) ? It seems that with higher aim my chance of poisoning the enemy heightens (tested with accuracy increase scrolls).