On the night of 27 November, three regiments from the 80th Division attacked the northern hills () and the inlet, completely surprising the defenders. The ensuing battle inflicted heavy casualties on the 1st Battalion, 32nd Infantry, to the north of Sinhung-ni, while the 57th Field Artillery Battalion and the 3rd Battalion, 31st Infantry, were almost overrun at the Pyungnyuri Inlet. The Chinese also sent the 242nd Regiment of the 81st Division towards Hill 1221 (), an undefended hill that controlled the road between Sinhung-ni and Hudong-ni. As the night's fighting ended, RCT-31 was separated into three elements.