It fought during the Invasion of the Japanese of Panay Island and resorted to guerilla warfare after the 61st Division surrendered on May 16, 1942.

However, in order not to create confusion it was renamed to 65th Infantry (Provisional) initially under Lieutenant Colonel Juan Quimbo former Division Chief of Staff,.

[1] The regiment participated in the Operation Baus Au initiated by General Chynoweth before he was ordered to assumed command of the new Visayas Force base in Cebu.

64th Infantry was assigned to Antique Province to thwart any Japanese landings but Naval and Air bombardment prevented them to do so due to absence of a single artillery gun in the Island.

However, this did not prevent Kawamura Detachment turnover Panay to 10th Independent Garrison to leave for Mindanao.