Zu Ti fought Later Zhao to a truce before having his authority diminished by the Jin imperial court due to concerns of a civil war back home.
During the siege, Zu Ti advised Ai to send an imperial edict to Yong's general, Liu Chen (劉沈), ordering him to attack his superior.
To avoid the chaos in the north, Zu Ti and a group of refugees decided to flee south of Yangtze River to Sikou (泗口, located at Xuzhou, Jiangsu).
After arriving in Sikou, Zu Ti was appointed the Inspector of Xuzhou and later the Army Libationer-Advisor by the Prince of Langye, Sima Rui.
[6] Zu Ti's first adversaries in his northern expedition were the refugees-turned-warlords, Zhang Ping (張平) and Fan Ya (樊雅), who had set up their fortresses in the princely fief of Qiao.
The two men recently submitted to Jin, so in 317, Zu Ti camped at Luzhou and had his Army Advisor Yin Ai (殷乂) pay them visits.
However, Zu Ti was running low on supplies, and he later moved to Taiqiu County (太丘; in present day Yongcheng, Henan).
Zu then attacked Fan but was caught in a stalemate, so he requested the Administrator of Chenliu, Chen Chuan (陳川), and the General of the Household of the South, Wang Han (王含) for reinforcements.
Wang Han dispatched Huan Xuan again to help Zu Ti, and together, they defeated and drove back Shi Hu.
Both sides suffered from food shortages, but Zu Ti was able to sell a false impression that his army was more well-supplied than Tao's, which demoralized the Later Zhao troops.
After 40 days, Tao Bao began to feel overwhelmed, so he fled during the night and retreated to Dongye (東燕, in modern-day Henan).
Zu Ti ordered Han Qian to place pressure on Tao from Fengqiu while Feng Tie occupied the rest of Junyi.
[10] At the same time, Zu Ti moved his base to Yongqiu and launched raids against the Later Zhao army, accepting many surrenders from their troops.
He also got the Jin generals Guo Mo, Li Ju, Zhao Gu (趙固) and Shangguan Si (上官巳), who were all stationed along the Huai River, to accept his authority after settling a quarrel between the four men.
Shi Le restored Zu Ti's grandfather and father's tombs as an act of good faith and offered to allow trade between them.
Zu Ti was so impressed at his display that he later ordered his followers to return any defector from Zhao and forbid them from pillaging Shi Le's land.
[11] While Zu Ti was campaigning against Shi Le, the tension between Sima Rui (Emperor Yuan of Jin as of 318) and his powerful general Wang Dun was beginning to reach its breaking point.
He camped at Hulao (虎牢, in modern Zhengzhou, Henan) intending to build a barrier south of the city to defend against invading forces, but before he could complete it, he succumbed to his illness in c.October 321.
[13] Wang Dun had long feared Zu Ti's strength, so he was relieved by the news of his death and became more eager to oppose Sima Rui.
"[15] After Zu Ti was transferred to a higher office, Liu Kun wrote to his relatives, "The spear is my pillow as I await dawn, for my ambition is to vanquish the enemy.