Teancum leads his men on a forced march towards Bountiful. He is not concerned with tiring his men, for they were heading toward safety. The Lamanite army, on the other hand, was tired from attempting to overtake them, and in that state they come upon Lehi’s “small army.” Even if the Lamanites might have had superior numbers, Lehi’s men were fresh, and the Lamanites were tired, which did not bode well for their prospects in hand-to-hand warfare.
Therefore, the Lamanites retreat, attempting to return to the safety of the city of Mulek.