In 208, after losing to Sun Quan and Liu Bei at the Battle of Red Cliffs, Cao Cao retreated north and left Cao Ren and Xu Huang to defend the strategic Jiangling Commandery (江陵郡; in present-day Jingzhou, Hubei) from the advances of Sun Quan's forces, which were led by Zhou Yu. Cao Ren was serving as acting General Who Attacks the South (征南將軍) then. Zhou Yu despatched a several thousand-strong vanguard to challenge Cao Cao's forces at Jiangling. Cao Ren was aware that his army's morale was low, since they were recently defeated at Red Cliffs, so he ordered his subordinate Niu Jin to lead 300 volunteer soldiers into battle, in the hope that they would display bravery and boost his men's morale. Niu Jin and his men were heavily outnumbered and surrounded by the enemy. Cao Ren's Chief Clerk (長史), Chen Jiao (陳矯), turned pale when he saw the situation from the top of the city walls. However, unlike what everyone thought, Niu Jin managed to create havoc around the Wu's army with just 100 men left by then. Cao Ren experienced a surge of fury and courage after watching how Niu Jin with so little men could make the entire Wu army three times the strength get so tired battling just 300 of his own men, so he ordered every troop in the city to be prepared to go into battle. Chen Jiao and the others attempted to dissuade him from braving danger, but Cao Ren ignored them and every soldiers in his command was ordered to charged into the enemy formation. Cao Ren successfully rescued Niu Jin and his surviving men and even turned back to save his remaining soldiers who were still trapped in the enemy formation. Sun Quan's forces retreated. When Cao Ren returned, his subordinates exclaimed, "General, you're truly a man from Heaven!" The troops were awed by Cao Ren's bravery, and Cao Cao was very impressed when he heard about this incident. Cao Ren's marquis title was changed to "Marquis of Anping Village" (安平亭侯).(從平荊州，以仁行征南將軍，留屯江陵，拒吳將周瑜。瑜將數萬衆來攻，前鋒數千人始至，仁登城望之，乃募得三百人，遣部曲將牛金逆與挑戰。賊多，金衆少，遂為所圍。長史陳矯俱在城上，望見金等垂沒，左右皆失色。仁意氣奮怒甚，謂左右取馬來，矯等共援持之。謂仁曰：「賊衆盛，不可當也。假使棄數百人何苦，而將軍以身赴之！」仁不應，遂被甲上馬，將其麾下壯士數十騎出城。去賊百餘步，迫溝，矯等以為仁當住溝上，為金形勢也，仁徑渡溝直前，衝入賊圍，金等乃得解。餘衆未盡出，仁復直還突之，拔出金兵，亡其數人，賊衆乃退。矯等初見仁出，皆懼，及見仁還，乃歎曰：「將軍真天人也！」三軍服其勇。太祖益壯之，轉封安平亭侯。) Sanguozhi vol. 9.
