Tian Lingzi
In spring 882, Emperor Xizong summoned Zheng to Chengdu, making him chancellor again, along with the titles of "Sikong" (司空, one of the Three Excellencies) and "Menxia Shilang" (門下侍郎, deputy head of the examination bureau (門下省, "Menxia Sheng")), giving him the most key responsibilities over the military matters. It was said that despite the imperial government's exile status, Zheng insisted on proper adherence to regulations—such that, by 883, by which time Huang had again abandoned Chang'an and Emperor Xizong was preparing to return to Chang'an, Zheng had offended the powerful eunuch Tian Lingzi and Tian's brother Chen Jingxuan, the military governor of Xichuan Circuit (西川, headquartered in modern Chengdu), as he rebuffed Tian Lingzi's request to have his assistant Wu Yuan () promoted and Chen's desire to receive greater honors than chancellors. Tian Lingzi and Chen thus instigated Li Changyan into submitting a petition that stated, "The soldiers are apprehensive. Therefore, when Your Imperial Majesty goes through Fengxiang, Zheng Tian should not follow." Zheng thus submitted his resignation. He was thus removed from his chancellor post and made a senior advisor to the Crown Prince. His son Zheng Ningji () was made the prefect of Peng Prefecture (彭州, in modern Chengdu), and Zheng was sent to Peng Prefecture to recuperate from an illness that he was apparently having at the time. He died soon thereafter.