You can try, but really, you can't beat Magic without Magic, given proper use. There are simply too many things you can't counter, or even handle.
It's no secret a Wizard, at any level, can end an encounter in just 1 round, given the right spells and skill. You can't match that, no matter how much damage you do - damage doesn't win D&D. At most, you can survive a bit longer before they wipe the multiverse with your dust.
That said, a well made Gish or even a Blaster/high DC Debuffer can beat a spellcaster fairly easily. Use magic to counter their defences, and kill them. A favorite trick of one of my old PC gishes was to counterspell enemy Teleport / Greater Mirror Image spells - he could do that as an Immediate Action.
Counterspelling can go a long way, if you know how to do it right. A spell is usually easier to Counter than Dispel, after all, if that's even possible.