Following the capture of the Royal Palace at Seoul and disarmament of the Korean troops, the Japanese began preparations for an attack against Chinese forces camped at Asan.

[2] The Chinese forces stationed near Seonghwan numbered about 3,880 men under General Ye Zhichao, and had anticipated the impending arrival of the Japanese by fortifying their position with trenches, earthworks including six redoubts protected by abatis and by flooding surrounding rice fields.

The defenders, after a sharp engagement, were unable to hold Seonghwan, and fled to Asan, ten miles to the southwest, leaving behind a considerable amount of weapons and stores.

[5] On 30 July, after the Japanese victory at Seonghwan, General Oshima's troops entered Asan undisturbed, and within the following week cleared the area of the remaining Chinese forces.

Clashes between Chinese and Japanese forces at Pungdo and Seonghwan caused an irreversible alteration to Sino-Japanese relations and meant that a state of war now existed between the two countries.