The newly constituted Huainan troops would soon be under severe test. Zhu Quanzhong, having conquered Tianping and Taining, decided to make Huainan his next target, so he gathered his available forces and sent Pang Shigu with 70,000 soldiers from Xuanwu and Ganhua Circuits to Qingkou (清口, in modern
Huai'an,
Jiangsu), posturing to head to Huainan's capital Yang Prefecture; Ge Congzhou with the forces from Tianping and Taining Circuits to Anfeng (安豐, in modern
Lu'an,
Anhui), posturing to head to Shou Prefecture (壽州, in modern Lu'an); and Zhu Quanzhong himself with his main forces to Su Prefecture (宿州, in modern Suzhou). The people of Huainan Circuit were greatly shocked and dismayed by Zhu's forces. However, Pang, because he had such an impressive force, underestimated Yang Xingmi's army. Yang Xingmi had Zhu Jin serve as his advance commander, and Zhu constructed a dam on the Huai River. When Yang Xingmi attacked Pang, Zhu released the waters to flood Pang's army, and then attacked Pang with Yang. Pang's army was crushed by the waters and the Huainan forces, and Pang was killed.
Zhu Yanshou also defeated Ge's army. Hearing that both of his generals had been defeated, Zhu Quanzhong also retreated. The
Battle of Qingkou thus affirmed Yang's control of the territory between the Huai and the Yangtze Rivers. After Yang died in 905 and was succeeded by his son
Yang Wo (who carried the title of Prince of Hongnong), Zhu Jin continued to carry the title of deputy supreme commander — a title that he continued to carry after Yang Wo was assassinated in 908 by the officers
Zhang Hao and
Xu Wen and succeeded by his younger brother
Yang Longyan. (Xu killed Zhang soon after their assassination of Yang Wo, and while thereafter Yang Longyan was prince, Xu effectively controlled the governance of the Wu state — which was an independent by that point after Zhu Quanzhong usurped the Tang throne in 907 and established
Later Liang as its Emperor Taizu, a title that Yang Wo and his successors refused to recognize.) Around the new year 914, the Later Liang general
Wang Jingren attacked Wu, to try to capture Wu's Shou and Lu (廬州, in modern
Hefei,
Anhui) Prefectures. Xu and Zhu Jin engaged Wang at Zhaobu (趙步, in modern Lu'an) and found themselves outnumbered, but Xu, with the assistance of the officer Chen Shao (), defeated Wang. Wang withdrew with heavy losses. Late in 914, then-Later Liang emperor
Zhu Youzhen (Zhu Quanzhong's son) tried to replace Wang Yin () the military governor of Wuning (who had been commissioned by his predecessor and older brother
Zhu Yougui, who had assassinated Zhu Quanzhong and taken the throne but was soon overthrown by Zhu Youzhen) with his cousin Zhu Youzhang (). Wang Yin, in fear, submitted to Wu and sought aid from Wu. Zhu Jin thereafter led a relief force to try to save Wang Yin, but he was intercepted and defeated by the Later Liang generals Niu Cunjie () and
Liu Xun; he thereafter withdrew. Niu and Liu thereafter captured Xu Prefecture, and Wang and his family members committed suicide. By 916, Xu Wen, who was still in control of Wu's governance, had removed himself from Yang Prefecture and permanently stationed himself at Sheng Prefecture (昇州, in modern
Nanjing,
Jiangsu), leaving his oldest son
Xu Zhixun in charge at Yang Prefecture. That year, the officers Ma Qian () and Li Qiu () seized Yang Longyan and launched their troops to attack Xu Zhixun. Xu Zhixun was fearful and decided to flee, but was dissuaded by the official
Yan Keqiu, and their opposing camps settled in that night. The next day, Zhu Jin, who had been stationed at Run Prefecture (潤州, in modern
Zhenjiang,
Jiangsu). Looking at Ma's and Li's camp, Zhu assured Xu Zhixun that there was nothing to be concerned about, and he yelled at Ma's and Li's troops; in fear, Ma's and Li's troops disassembled, and they were captured and executed. In winter 916, with Li Keyong's son and successor
Li Cunxu the Prince of Jin requesting Wu to enter an alliance to jointly attack Later Liang, Xu Zhixun and Zhu Jin led troops north toward Song (宋州, in modern
Shangqiu,
Henan) and Bo (亳州, in modern
Bozhou,
Anhui) Prefectures. They crossed the Huai River and put Ying Prefecture (潁州, in modern
Fuyang,
Anhui) under siege. In spring 917, however, after Zhu Youzhen dispatched the general
Yuan Xiangxian to aid Ying Prefecture, the Wu troops withdrew. == Death ==