As planned, the first Civil Guard battalion of Task Force A started north towards Ap Bac. Hoang knew the Civil Guard battalions were approaching, so he instructed his company commander in Ap Bac to be ready, as they would fire the first shots of the battle. VC radio operators, using captured US communications equipment, followed the movements of the Civil Guards by monitoring the frequencies the government troops were using. When the leading Civil Guard battalion came within of the south end of Ap Bac, the VC opened fire from their foxholes and immediately killed the leading company's commander and wounded the task force commander. Task Force A's momentum was stopped when the soldiers of the leading Civil Guard battalion sought shelter in a dike, where they tried unsuccessfully to outflank the VC. During that time, artillery support was ineffective, as Civil Guard forward observers would not stand up to observe the fall of artillery rounds. Consequently, one artillery round after another fell behind VC positions, instead of on their foxholes. To make matters worse, Tho failed to send his second Civil Guard battalion of Task Force B to rescue the first.