If you have closed the distance, your primary goal is to control the enemy. This means controlling his ability to influence the rest of the fight, and controlling his ability to damage you. You are essentially stalling until someone can come to your aid.
a. Body Control. You must control the enemy’s ability to move, which can done by gaining and maintaining a dominant body position. This can also be accomplished by pinning the enemy in place (for example, against the wall).
b. Weapon Control. You must immobilize the enemy’s weapon. For example, use your weight to pin his rifle to his chest while you are mounted, or keep him from drawing a side arm by controlling it in the holster. You must also keep your weapons away from the enemy. It does you no good to immobilize the enemy if he can reach your side arm.