Castruccio had noticed how the enemy had placed all his best troops in the centre of the line of battle, and his less reliable men on the wings of the army; whereupon he did exactly the opposite, putting his most valiant men on the flanks, while those on whom he could not so strongly rely he moved to the centre.

Observing this order of battle, he drew out of his lines and quickly came in sight of the hostile army, who, as usual, had come in their insolence to defy him.

He then commanded his centre squadrons to march slowly, whilst he moved rapidly forward those on the wings.

Thus, when they came into contact with the enemy, only the wings of the two armies became engaged, whilst the center battalions remained out of action, for these two portions of the line of battle were separated from each other by a long interval and thus unable to reach each other.

By this expedient the more valiant part of Castruccio's men were opposed to the weaker part of the enemy's troops, and the most efficient men of the enemy were disengaged; and thus the Florentines were unable to fight with those who were arrayed opposite to them, or to give any assistance to their own flanks.
So, without much difficulty, Castruccio put the enemy to flight on both flanks, and the centre battalions took to flight when they found themselves exposed to attack, without having a chance of displaying their valour.