Lü Fan
Sun Lang's misfortune occurred in 222, shortly after Sun Quan's triumph over Liu Bei at the Battle of Xiaoting. The emperor of Cao Wei, Cao Pi, launched a multi-pronged invasion against Eastern Wu. One prong was led by Cao Xiu, who led his army to Dongkou, which was defended by Lü Fan. Sun Lang was acting in capacity as a guardsman of the palace at the time and thus was under Lü Fan's authority. However, early in the battle, he accidentally set fire to his own camp, destroying a large quantity of supplies in the process. To compound the Wu forces' difficulty, a freak storm struck at Lü Fan's fleet, sending it crashing along the northern shore. Those troops in Lü Fan's fleet who did not drown were then in danger of either being attacked by Cao Xiu's troops or dying of starvation. Luckily for the Wu forces, the general Xu Sheng arrived, driving back Cao Xiu's forces long enough for Lü Fan to regroup, and in the end, Cao Xiu's fleet was driven back.