 In spring 537, Gao Huan and his generals Dou Tai (竇泰) and Gao Aocao (高敖曹) launched a major attack on Western Wei.Yuwen, correctly judging that Gao Huan was trying to draw Yuwen toward him while allowing Dou to penetrate Western Wei defenses, announced that he was going to lead a withdraw to modern eastern Gansu but instead made a surprise attack on Dou's army at Xiaoguan (小關, in modern Sanmenxia, Henan), crushing Dou's forces.Dou committed suicide in shame.