Japanese forces, mainly the 5th Division and 11th Independent Mixed Brigade, moved out from Beiping and advanced on Huailai County in Chahar.

By the time they reached the Shanxi border, Lin Biao's 115th Division, after a forced march from Shaanxi, was in place at Pingxingguan on 24 September to ambush the Japanese army.

Lin's division were able to ambush two columns of mainly transportation and supply units and virtually annihilate the trapped Japanese forces.

On 25 September, the 21st brigade of the Japanese 5th Division stationed at Lingqiu received a request from the 21st Regiment that they urgently needed supplies due to falling temperature.

The supply troops of the 21st Regiment set out with 70 horse-drawn vehicles with 50 horses, filled with clothes, food, ammunition and proceeded westwards towards Pingxingguan.

Lin Biao's troops eventually withdrew from the battlefield, allowing the Japanese to finally reach the site of the ambush on 28 September.

On the other hand, the Communists' accounts describe Pingxingguan as a typical example of Red guerrilla tactics, inspired by Mao Zedong's conceptualization of people's war.