An important secret in defeat a Boxer is controlling spacing, and this is excellently accomplished with body movement

The Bow-Arrow Stance is very useful in deflecting a Boxer's strikes. If the strikes are relatively far from you, deflect them away with your guard-hands. If they are penetrating, sink back your body without moving your feet and simultaneously deflect the strikes away. Notice that by sinking your stance, the Boxer's strikes cannot reach you even if you had not used your guard-hand to deflect them, while your guard-hand keeps the Boxer at bay.