At Cao Caos instruction， Liu Bei was about to set off for a punitive expedition against Yuan Shu. Before he left， Liu Bei worried about the defence of Xuzhou City. When Zhang Fei volnteered to take the task， Liu said， How can I feel assured， when youre so fond of drinking and after drinking you always flog your soldiers for no reason？ And youre such a hot-tempered person and frequently you refuse to take advice. He entrusted the task upon Zhang only after the latters repeated entreatments and resoltions to mend his ways. For safety， he left consultant Chen Deng to assist Zhang . One day Zhang invited his subordinate officers over. My elder brother instructed me before he left to stay away from wine for fear I may fail my duties to guard the city. Lets have an final drinking party today， and starting from tomorrow， we will quit drinking and concentrate on the job . With these words said， he began toasting everyone. When neither of his toasts was accepted by Cao Bao， Zhang flared up ， By then ， Zhang was already drunk. He had Cao flogged fifty times. After the party was over， the resentful Cao sent one of his men to L Bu， the enemy general， asking him to attack the city that night while Zhang was drunk. L came with 500 horsemen. They successfully took the city. When Zhang woke up with a start， the city was gone. He fought his way out of the enemy troops and fled the city， leaving his elder brothers family behind. When he met Liu， he felt so shame-faced that he unsheathed his sword meaning to commit suicide， only to be stopped by his elder brother.
曹操命刘备伐袁术，刘备临行时为由谁留守徐州拿不定主意。这时，张飞请求留守徐州。刘备却说：你一是爱喝酒、耍威风、鞭打士兵，二是办事草率不听人劝。让你留守，放心不下。张飞愿改过并再三请求，刘备答应张飞，并派陈登协助。一日，张飞请留守各将赴宴，说：我大哥临走时不让我喝酒，怕酒后误事，今天请你们来一醉方休，从明天起全都戒酒，帮我守好城池。说罢便轮番敬酒，当二次到曹豹面前劝酒时，遭曹豹拒绝。这时张飞已醉，命鞭打曹豹五十鞭。散席后，曹豹怀恨在心，便连夜派人送信给吕布，让他今夜乘张飞大醉偷袭徐州。
吕布当夜领五百轻骑取得徐州。呐喊声震醒张飞，知徐州已失，顾不得刘备的家眷，边战边逃。后张飞见到刘备，悔恨万分，欲抽剑自刎，被刘备死死拦住。