The deaths of Liu and Han, both of whom were close associates of Emperor Wen, brought fear into the heart of another associate of Emperor Wen—Hua Jiao () the governor of Xiang Province (湘州, modern central Hunan). In summer 567, Hua therefore submitted himself to Northern Zhou and Northern Zhou's vassal state, Western Liang. Chen Xu sent Wu and Chunyu Liang () to lead a fleet against the joint forces of Hua, Northern Zhou, and Western Liang. The opposing sides met at Dunkou (沌口, in modern Wuhan, Hubei). Wu and Chunyu were able to ram Hua's, Northern Zhou's, and Western Liang's fleets, causing them to collapse. Both Hua and the Northern Zhou general Yuwen Zhi () the Duke of Wei fled to Western Liang's capital Jiangling (江陵, in modern Jingzhou, Hubei), while the Northern Zhou general Yuan Ding () were captured. Wu followed up by putting Jiangling under siege in spring 568, but was not able to capture it and subsequently forced to withdraw.