If he wants you to chase him, don't. Never play by the enemy's rules.
The easiest solution is not to follow. Stand your ground and ready an attack. If the enemy comes back in toward you, he gets that move and a single attack. You get your readied action right them, plus a full attack on your next action. You clearly come out ahead, and if he retreats again you gain even more advantage. Meanwhile, your archers and spellcasters should be unloading on him.
Another solution is to use magic to modify the battlefield to your advantage. Wall spells are great for this. A particular favorite is to create a wall of force six inches off the ground, twenty feet ahead of the enemy, in the direction he's trying to escape. It's invisible, so unless he has Spellcraft or makes a Spot check over DC 40, he'll probably run straight into it.
The easiest solution is not to follow. Stand your ground and ready an attack. If the enemy comes back in toward you, he gets that move and a single attack. You get your readied action right them, plus a full attack on your next action. You clearly come out ahead, and if he retreats again you gain even more advantage. Meanwhile, your archers and spellcasters should be unloading on him.
Another solution is to use magic to modify the battlefield to your advantage. Wall spells are great for this. A particular favorite is to create a wall of force six inches off the ground, twenty feet ahead of the enemy, in the direction he's trying to escape. It's invisible, so unless he has Spellcraft or makes a Spot check over DC 40, he'll probably run straight into it.