The Chinese believed that Sacheon was crucial to their goal of retaking the lost castles in Korea and ordered a general attack. Although the Chinese made initial progress, the tide of battle turned when Japanese reinforcements attacked the rear of the Chinese army and the Japanese soldiers inside the fortress sallied from the gates and counter-attacked. The Chinese Ming forces retreated with 30,000 losses, with the Japanese in pursuit. According to Chinese and Korean sources concerning the battle, the forces led by Dong Yi Yuan had breached the castle wall and were making progress in capturing the castle until a gunpowder accident caused an explosion in their camp, and the Japanese took advantage of the situation to rout the confused and weakened troops.