On the night of November 8, the 1st Brigade of the 73rd Wing of the 19th Division of the Japanese Garrison Army rested in Wenjing, and in the early morning of the 9th, the 3rd Squadron of the Brigade marched to Beizhen as an advance team, with the ultimate goal being Bitong. The road to Beizhen was safely traversed by the 2nd Brigade last night, so it is not unreasonable that the 1st Brigade did not take special precautions. The road ahead is a slender valley about 1,000 meters wide that opens to the mouth of the Onui River, and is flanked by steep mountains about 150 to 300 meters high with rocky muscles and mixed forests.

A column of more than a dozen Isuzu trucks pulling the 3rd Squadron entered the pass of the two water holes, and completely unexpectedly immediately came under heavy fire from the front and the high ground to the left and right. A rear guard unit of the 20th Mountain Division of the Eighth Army of the Chinese National Defense Force, which had infiltrated the Wenjing area two days earlier, would encounter the logistics units of the 20th Division if the Japanese were allowed to advance again.

The 20 th Mountain Division of the Eighth Group Army of the National Defense Army, as the first batch of combat troops, was ordered to advance to Wenjing after secretly entering South Korea, and the division commander Qiao Zheng and chief of staff Zhang Yuhua, according to the instructions of their superiors and the situation at the time, judged that the enemy had occupied Wenjing and might continue to advance northward, so they ordered the troops to seize the 216 heights northwest of Wenjing to the first-line heights of Beizhen to prepare for battle. At about 9 o'clock on the 25th, when the 3rd Squadron of the Japanese Army rushed from Wenjing to Beizhen to Liangshuidong, 13 kilometers west of Wenjing, the 2003 Regiment of the 20th Division quickly attacked, using the mortar fire of the regiment to carry out a continuous attack on the enemy's automobile troops.

The other units of the 73rd Wing of the 19th Division of the garrison army quickly approached the area of the firefight, judging from the number of firepower points, the opponent's strength was not much, and immediately launched an attack, but the more they advanced, the more fierce the enemy's firepower became, and the situation seemed to be very different from the situation judged by the Japanese army, at this time they did not realize that the Chinese army on the opposite side had been reequipped with "repeater" semi-automatic rifles, and a large number of old Madsen light machine guns had been decommissioned, in addition to one "ruler" general-purpose machine gun per platoon, a large number of "shockers" Submachine guns and Type 08 grenades complemented semi-automatic rifles, giving the Chinese Defense Force's grassroots firepower more than five times superior to that of the Japanese army. Soon, it was realized that the rear was cut off, and the 73rd Wing was surrounded in a river valley without any support.

Although there is not much difference in the strength of the two sides, the 73rd Wing of the Japanese Army has 3,747 people when it is fully manned, which is just twice the number of the 2003 Regiment and a mountain howitzer company attached to it, but the difference in firepower makes this numerical advantage completely invisible. After a while, several companies of the 2003rd Regiment of the Wehrmacht began to flank the various battalions of the 73rd Wing. The assault soldiers, each with a dozen grenades on their chests, approached under the cover of fire from the heights on either side, firing grenades in unison with the sound of a whistle, and approaching with the barrage. The password can already be heard and clearly Chinese. The Japanese had to believe that it was the field units of the Chinese National Defense Forces that had beaten them to the point of being powerless.

The command structure of the 73rd Wing was destroyed in an instant, and the officers and men lost their equipment and fled in all directions. At that time, the 73rd Wing had 2,750 personnel (some of the baggage soldiers and artillery were on the way from Akutagawa), and less than 1,400 officers and men were evacuated to Onkai in the afternoon, and 1,350 officers and men, including Takeshita Nakasa, attached to the wing, were lost in this instant battle, and all technical equipment.

The baggage troops of the 73rd Wing, which was ready to go at Onjeong, and a regiment of the 5th Division of the Samhan Yasukuni Army, which was regarded as a civilian man, knew that the situation ahead had changed and hurriedly set off, when they found that the enemy was moving on the high ground on both sides. The Japanese rearguard stopped and sent scouts in all directions, and soon knowing that the retreat was cut off, they hurriedly occupied the ring position. At night, when the Yasukuni Army saw that it was difficult to open up a retreat, they threw away their equipment and ran to the mountains on the south side, and were able to return to Wenjing late at night. The baggage brigade of the 73rd Wing in Wenjing was also overwhelmed by the rapid deterioration of the situation and urgently set up a position.

At 14:30, the 20th Regiment of the 2003rd Mountain Division took the initiative to attack, and a two-company battle group annihilated the top squadron of the 3rd Brigade of the 73rd Wing of the Japanese Army and the mountain artillery squadron of the Wing that advanced to Liangshuidong and Cangdong. The main force of the 2nd Brigade of the Japanese Army was to rescue the 3rd Brigade that was besieged, and with the strength of one squadron, it attacked the 9th Company of the 216th Regiment and the 2003rd Regiment holding the 2003 heights more than 10 times, but they were all repulsed. The battle ended at 15:30, the Japanese casualties were unknown, 17 people were killed in the 9th Company, 34 were seriously wounded, and they had lost the ability to continue the offensive and switched to local defense.

In this battle, the 2003 Regiment of the 20th Mountain Division adopted the tactics of blocking the front and intercepting the rear, blocking the waist and cutting off, annihilating an infantry brigade and an artillery squadron of the Japanese army, killing and wounding 1,484 prisoners, capturing 23 Japanese officers and soldiers, and capturing 1,163 guns of various kinds, 12 artillery pieces (8 guns were scrapped), and 8 cars (all scrapped). That night, the 2003rd Regiment, together with the logistics troops of the 20th Mountain Division, took advantage of the victory to capture the village of Doi on the outskirts of Wenjing, and once again annihilated a Japanese baggage brigade. On November 10, Lieutenant General Wu Luzhen, the headquarters of the Eighth Army, sent a telegram to the headquarters of the 20th Mountain Division and the 2003 Regiment: "Celebrate your victory in the first battle of the Eighth Army into Korea. ”

In the early morning of the 11th, the 74th Wing, with the strong support of the main force of the 19th Cavalry Brigade of the 19th Division and the 19th Independent Mountain Artillery Brigade, set out from the Longshan Lake-Yongbyon line and advanced rapidly with Shuifengba as the goal. Although Wing Commander Utagamiya Daisa was summoned by Lieutenant General Dai-tei Jiro of the garrison in Pyongyang to leave the fighting ranks, the morale of the Tun Wing of the Garrison Army, which had been known for its bravery and good fighting since the beginning of the war, remained high.

The 74th Wing, led by the 19th Cavalry Brigade, caught some stragglers of the Samhan Restoration Army who were retreating in groups of three or five on the way, and because they were in a hurry to march, they were escorted to the side of the road and shot or beheaded. When they reached Yunshan, they did not find the enemy. From Yunshan to the north is the Diyu Mountains, and if you cross the Jiangnan Mountains, it is the surging Yalu River. As soon as the cavalry team, which was hurrying north without pause, arrived at the Chaoyang Bridge erected over the Santan River, it was met with sudden concentrated fire from howitzers.

However, the Japanese 74th Wing was still a well-trained field unit, although the terrain was unfavorable, and it was attacked by artillery fire on the march, but the Japanese infantry was quickly dispersed and hidden, and after the artillery fire was sparse, under the organization of the officers and soldiers, they began earthwork, digging fortifications, and preparing to resist the enemy's infantry attack, so that the artillery ambush of the Eighth Army also severely damaged the cavalry brigade that was crossing the river, and the losses of the 74th Infantry Wing and artillery behind were not large, and the other side was deployed along the river embankment, The use of the anti-slope of the river embankment to build fortifications made the Wehrmacht's howitzers useless, and soon the shelling had to be stopped.

Although it is only an infantry wing of the Samhan garrison, the proportion of veterans in the wing is very high, and the training is no worse than that of the standing divisions in the country. How did the Japanese army train it? From the beginning of enlistment, it is stick education, absolute obedience, not only infantry skills are practiced hard every day, even digging trenches is meticulous training, not to shovel up the soil and still outside, but to fill the soil after turning around, facing backwards, shovel handle upwards, and then turn around and face forward, kick the back foot, and then throw the soil, arm strength, waist strength and foot strength are all used. The soil thrown out is accurate and far away, and this action is repeatedly trained until it is clean and neat, and all fortifications camouflage, side defense, obstacle opening, and close work must be practiced day and night.

Moreover, the Japanese army in this year had a strong attacking spirit, and could charge more than ten times a day without losing its sharpness, and liked to attack in tunnels. For example, in the Battle of Heigoutai between Japan and Russia, after the Japanese army carried out close forcing operations against the 5th Division of the Russian Far East, it suddenly began to charge at close range. The Japanese infantry worked hardest in field education, shooting education, and night education. When attacking, he likes to use a cone-shaped frontal assault, one wing encirclement and two sides encirclement, and flexibly interspersed in the mountains. After this battle, the Wehrmacht gradually realized that the elite combat effectiveness of the Japanese army was not below itself, and if it only relied on advanced weapons and massive ammunition, and did not have the real ability to dare to sacrifice and be good at fighting tough battles, then it is still unknown who will lose and who will win in this war between China and Japan in Samhan. Recognizing the strength of the enemy, the Wehrmacht began to face up to the opponent in a real way, made full use of its own equipment and logistical advantages, and began to learn to fight with its brains, rather than simply fighting the routine of artillery bombarding the infantry.

At 19:30 on the evening of the 11th, the Eighth Army was scheduled to launch the Yunshan Campaign. According to the deployment of the group army headquarters, Qiao Zheng, commander of the 20th Mountain Division, decided that the 2001 Infantry Regiment would serve as the main attack, and the 2002 Infantry Regiment and the 2006 Air Defense Regiment would coordinate to encircle and annihilate the main force of the 74th Wing of the Japanese Army and the 19th Cavalry Brigade and other auxiliary forces in the Yunshan area.

During the day that day, Qiao Zheng, commander of the 20th Mountain Division, hurried to make the final pre-war preparations. However, in the afternoon of that day, a staff officer on duty came to report that there was unusually frequent activity on the enemy's position, and that an unexpected new situation had emerged. He immediately rushed over to observe, and found that the vehicles and soldiers of the opposing position were coming and going, and there was chaos. He believed that the defenders of the Samhan Yasukuni Army and a brigade of the Japanese army at Unsan Fortress were preparing to retreat. The generals of the Chinese National Defense Forces have a deep-rooted tactical principle, that is, if they seize the enemy, they must not let him escape, and even if they do, they will not be fought, and they will be criticized for attacking and routing. In order to prevent the enemy from escaping, Qiao Zheng suggested to the head of the Eighth Army to launch an attack immediately, and Commander Wu Luzhen quickly approved Qiao Zheng's suggestion. The Battle of Yunshan began more than two hours ahead of schedule.

At 16:40 p.m., the fire support regiment (2004 regiment) of the 2004 Mountain Division of the Wehrmacht, in a hurry, began artillery preparations. Colorful signal flares rose into the air in the twilight sky, and the sound of artillery of various calibers shook the Yunshan Valley. Immediately following the artillery fire, two regiments of Wehrmacht mountain infantry began to attack the mountain of Unse.

According to Qiao Zheng's pre-war deployment, the 2001 and 2002 regiments attacked from the right flank and the left flank respectively, and the battle went very smoothly. Although the Japanese army used infantry artillery, mortars and other firepower to resist desperately, the 20th Mountain Division gave full play to the advantages of sniper, mortar rapid coverage and shooting, and flexible interspersed with mountain troop squads, and quickly attacked Unsan City, and after defeating the defense of a Japanese garrison brigade, the Sanhan puppet army in Unsan City completely herded sheep. Although Yunshan changed hands, it was obviously unrealistic to rely only on two mountain artillery companies and divisional teams directly under the division to block the reinforcements of the Japanese 74th Wing, so the war clouds over Yunshan had not yet dispersed.