In 248, Ezhesai (蛾遮塞) and the Qiang rebels occupied fortresses in Heguan (河關; in the vicinity of present-day Dingxi, Gansu) and Baitu (白土; in present-day Minhe County, Qinghai) counties and used them as defences against Wei forces across the Tao River. Guo Huai pretended that he was going to attack from upstream, but actually secretly ordered his troops to cross the river downstream to attack Baitu. The assault was successful and the rebels were defeated. Zhiwudai (治無戴) led his tribal forces to attack Wuwei Commandery but left his family in Xihai Commandery (西海郡; near the Juyan Lake Basin, Inner Mongolia). When Guo Huai learnt about it, he led his troops to attack Xihai Commandery, but encountered Zhiwudai and his forces, who were on their way back from Wuwei Commandery. The two armies clashed at the north of Longyi County (龍夷縣; west of present-day Huangyuan County, Qinghai), with the Wei forces emerging victorious and Zhiwudai's forces retreating.