The description of this engagement with the Lamanite army is sparse. When Teancum killed Amalickiah, it had a great effect on the Lamanite army, and they fled. In this case, we don’t hear whether or not they were in any disarray, but Mormon does note that Moroni came upon them the very next day. If there was any advantage to be seized, it was to be seized soon, and Moroni did just that.
The Lamanites were driven out of the land. The thirty-first year ends. Mormon declares in his frequent literary fashion, that there was a stark contrast between the many years of war, bloodshed, and famine, and the result of this campaign, which was freedom from those troubles for the space of many years.