When the battle had reached its climax, Chun Shenjun and Zhan Lang made decisive changes to their formation.
Chiyou camp's 7 thousand sword-shield infantry and archers pushed forward and assaulted Di Chen's forces which were at the farthest corner. The difference in numbers, even if Di Chen had better equipment and experience, was too much for him to handle.
Seeing that they were about to collapse, Ouyang Shuo didn't leave them in the lurch and ordered the allied troops to assist. At the same time he requested assistance from Chang Xian. Ouyang Shuo understood the theory of if the lips die the teeth will start to feel cold.
Unfortunately, Chun Shenjun had changed their tactics too quickly, and once they realised that Ouyang Shuo's cavalry wasn't there, they immediately attacked Di Chen. When the troops led by Ouyang Shuo and Chang Xian reached to assist, it was too late and Di Chen's forces had been utterly destroyed.
