The Macedonian war machine was a system of two parts. The Phalanx (the Anvil) held the enemy in place, while the Companion Cavalry (the Hammer) delivered the killing blow.
The Macedonian Phalanx was unlike anything the world had seen. Armed with the 18-foot sarissa pike, they formed an impenetrable wall of spear points. No enemy could get close enough to strike them.
Led by Alexander himself, these were the elite shock cavalry of the ancient world. While the enemy exhausted themselves trying to break the phalanx, Alexander would lead the Companions in a wedge formation, smashing into the enemy's flank or rear.
Result
Total envelopment and psychological collapse of the enemy force.