Meanwhile, an ally of Zhu's, Du Hong the military governor of Wuchang Circuit (武昌, headquartered in modern Wuhan, Hubei), had been under attack by Yang for several years and was in a desperate situation. Zhu sent his general Han Qing () south to try to save Du, while also requesting Cheng, Ma, and Lei Yanwei the military governor of Wuzhen Circuit (武貞, headquartered in modern Changde, Hunan) to launch troops to save Du. Cheng agreed and launched a fleet, which he himself commanded, toward Wuchang. However, after Cheng left his capital Jiangling, Ma sent Xu to join forces with Lei's officer Ouyang Si () to attack Jiangling. They captured it, pillaged it for its population and wealth, and then withdrew. Cheng's army, hearing that their families and wealth had been captured, lost its morale, and was subsequently defeated by Yang's general Li Shenfu; Cheng committed suicide by drowning. On the way back to Tan, Xu met with Deng Jinzhong () the prefect of Yue Prefecture (岳州, in modern Yueyang, Hunan) and persuaded Deng that he should submit to Ma. Deng agreed, surrendered the prefecture, and moved his entire family to Tan to show submission to Ma. Ma made Xu the prefect of Yue and Deng the prefect of Heng.