As soon as the two forces clashed, Mei Cheng pretended to surrender to Yu Jin, and then led his men to join Chen Lan at Mount Tianzhu as soon as Yu Jin and Zang Ba left. On the other hand, Zhang Liao was worried that Cao Cao's rival, the warlord Sun Quan, would send his general Han Dang with an army to assist Chen Lan. Han Dang was in charge of defending Wancheng (皖城), a major stronghold in Lujiang Commandery at the time, so Zhang Liao sent Zang Ba to attack Wancheng so as to ensure that Han Dang could not move to reinforce the rebels. Zang Ba attacked Wancheng, but Han Dang defended the city well and succeeded in driving Zang Ba back. Later Sun Quan dispatched an army of some 20,000 to 30,000 troops to assist Chen Lan but Zang Ba was able to ambush and drive away the reinforcements sent by Sun Quan. However, Zang Ba did not stop there as he gave chase at night and attacked in the morning. Many soldiers of Sun Quan could not board their ships, and were forced into the water and drowned. Without the intervention from Sun Quan, Zhang Liao suppressed Chen Lan's rebellion and both he and Mei Chen were killed.