1 Samuel 11:11

They came.; in the morning watch. By a forced march Saul came upon the unsuspecting Ammonites just before daybreak, when sleep is deepest; and as his host was unwieldy, he arranged it in three divisions, assigning to each a different route, that they might not impede one another on the way, and might also cut off the retreat of the enemy. As the fighting went on for five or six hours, until the heat of the day, the Ammonites must at first have made some resistance; but when all three divisions of Saul's army had come up, they were so utterly routed that "no two of them were left together."