If the enemy sees you first, you are dead.
If you see the enemy first, you have control of how the fight plays out. You can hide, run away, or launch a sneak attack.
If you can outrun the enemy, or move through a terrain they can't (Flight, Swimming, Burrowing) then you escape.
If the enemy catches up, you need to be able to survive at least one hit. (In some cases, reflecting damage can cause more damage than you can deal normally if the enemy is strong enough, so that can be an invaluable skill.)
After that, try to instantly heal up to full so you can take another hit. Recovery of mana and stamina are equally important, as running out of the resources that allow you to escape or cast defensive spells is death.
If the first hit manages to destroy your equipment, then surviving the next hit may become impossible, so you also need to be able to repair or create new equipment in the heat of the moment.