With the defeat of the Ja'un-i Qurban and Togha Temur, the Sarbadars still had one more force to contend with in Khurasan: the Kartids of Herat. Their leader Mu'izz al-Din Husain also recognized Togha Temur's overlordship, and when the Sarbadars threw off the khan's nominal rule, they became enemies. The Sarbadars decided to destroy the Kartids with an offensive campaign. The armies of the two forces met at the Battle of Zava on July 18, 1342. The battle started out well for the Sarbadars, but then Hasan Juri was taken and killed. His supporters, assuming (perhaps correctly) that his death had been the result of an assassin of Mas'ud, promptly retreated, turning the tide of the battle. The Kartids therefore survived. Following the return home, Mas'ud attempted to rule without the support of the dervishes, but his power was decreased. He attempted to end the threat of Togha Temur, who had in the meantime made his camp in the Amul region and was preventing the Sarbadars from staying in contact with the Chobanids. Mas'ud undertook a campaign against him in 1344 which got off to a good start, but ended in disaster. On the route from Sari to Amul, the Sarbadar army was trapped in a pincer movement, and Mas'ud was taken prisoner and executed. Most of the Sarbadar conquests were lost as a result of the two losses; only the region around Sabzavar, as well as maybe Juvain and Nishapur remained in their hands. Togha Temur returned to Gurgan and once again gained the allegiance of the Sarbadars.