At 0800 on 5 December the 184th and 17th Infantry Regiments moved out with the 184th Infantry on the left. The 1st Battalion, 184th Infantry, on the extreme left, reached the Palanas River without incident and without having to fire a single shot.[55] The Japanese historians, however, claimed that one of the amphibian tanks was set on fire and that the 2d Battalion, 12th Independent Infantry Regiment, repulsed the advance of the 184th Infantry.[56]

There were numerous finger ridges inland which were cut by deep ravines and gorges that came to within a few hundred yards of the coast line. The entrenched Japanese, using reverse slope tactics, were able to deliver deadly fire on the advancing infantry. In many cases the reverse slopes were so steep that effective artillery fire could not be placed upon them.[57] The 2d Battalion, 184th Infantry, moved forward slowly toward a small hill which faced the Palanas River, and at 0858 it encountered enemy small arms fire from the western slope of the hill. Using grenades, the battalion pushed forward, but at 0938 the Japanese opened up with three light machine guns. The supporting weapons of the 2d Battalion fired on the enemy positions to the front. At 1037, as the battalion reached the military crest of the hill, the Japanese launched a small counterattack on the left flank of Company E. This attack was repulsed, but the companies continued to receive small arms and machine gun fire.

At 1325 the 1st Battalion renewed its advance and proceeded without incident, finding the situation “very quiet” to its front. At 1435 the battalion dug in for the night approximately 300 yards south of Balogo.[58] The 3d Battalion moved through the gap between the 1st and 2d Battalions and across the front of the 2d Battalion on the right toward Hill 380, which consisted of a series of ridges. As the 3d Battalion advanced toward the hill, it came under machine gun fire on each flank. With artillery support, the troops reached the top of the second ridge of Hill 380 and dug in, nine of the men having been wounded.[59] At 1635 the battalions of the 184th Infantry received orders to set up night defense positions in depth and to hold the “positions at all costs.”[60] Colonel O’Sullivan decided that the 3d Battalion was to bear the brunt of the advance of the 184th Infantry on 6 December and push on to Hill 380.[61]

On the right of the 184th the 17th Infantry had had a busy day in working toward its objective, Hill 918. At 0800 on 5 December the 1st and 2d Battalions of the 17th Infantry, with the 1st Battalion on the left, had moved through the 32d Infantry. At 0906 the advance elements of the 1st Battalion secured a ridge south of the main ridge leading from Hill 918, and at 1000 the entire battalion closed on this ridge. In the face of sporadic rifle and machine gun fire, the leading platoons pushed forward to secure a ridge that led west from Hill 918. As the advance platoons neared the crest of this ridge, they received intense rifle, machine gun, and mortar fire to the front and on both flanks from the 2d Battalion, 12th Independent Infantry Regiment. At the same time the rest of the battalion, in attempting to reach a forward ridge and support the leading platoons, also encountered cross fire that came down the intervening draw. As enemy gunfire pinned down the troops, the 1st Battalion lost contact with Company G, 2d Battalion, and a gap developed between the 1st and 2d Battalions.

The 12th Independent Infantry Regiment, quickly alert to exploit this opportunity to drive a wedge between the two forces, threw approximately a company armed with machine guns and mortars into the gap. Although they did not penetrate completely, the enemy troops were able to secure a position which would make any forward movement of the 1st Battalion very costly. The 1st Platoon of Company B and the 3d Platoon of Company A were still out on the forward ridge and cut off from the rest of the battalion. The reserve platoon of Company A tried an envelopment around the right flank of the 1st Battalion but was stopped by the enemy in the gap. Company C moved up to protect the rear of Company A. Eventually the forward platoons withdrew to the battalion lines and preparations were made for the night. Under cover of darkness the 1st Battalion reorganized and moved into positions on top of the first ridge.[62]

Earlier that day the 2d Battalion had driven forward with Company E on the right and Company G on the left. Company E went east along the Bucan River for approximately 1,000 yards and then turned northeast to ascend Hill 918. At first, however, the company had to secure a small ridge southwest of Hill 918 on which was a small but dense banana grove. Company E encountered and destroyed a small enemy force on this ridge, after which the company reorganized and at approximately 1300 began to ascend Hill 918 itself. When Company E reached the military crest of the hill, the Japanese began heavy firing with grenade launchers and at least three machine guns. The enemy fire swept the crest of the hill and prevented any movement over the lip of the ridge.

Meanwhile, Company G went to the left of Company E and secured a small ridge about 1,200 yards from the line of departure and west of Hill 918. The advance platoon of Company G then received fire from automatic weapons that were emplaced in a draw to the left front of the platoon. The rest of the company attempted to move around to the right of the ridge but also encountered automatic weapons fire coming from another draw. Since high cogon grass covered the area, observation was limited to a matter of inches. At about 1300, elements of the 13th Independent Infantry Regiment counterattacked through a gap between Company G and Company A of the 1st Battalion. A machine gun platoon, which was thrown in to plug the gap, succeeded in stopping the attempted Japanese advance.

Company G, however, continued to be pinned down by the enemy fire directed at its front. Company F, the reserve company, was then committed to take a position between G and E Companies. Its mission was to come abreast of Company E, take Hill 918, and then turn west and wipe out the resistance in front of Company G. At 1415 Company F moved up Hill 918 and reached Company E without opposition.

Three spurs led down from Hill 918. The one occupied by Company E ran southwest, that occupied by Company F ran west, and the third ran northwest. As the two commanders started to launch a co-ordinated assault from their respective spurs, their companies received a concentration of about fifty rounds of mortar fire but pushed through this fire and secured the crests of both spurs. They immediately came under automatic weapons and rifle fire from the northwest ridge.

Since the left flank of Company F was in the tall cogon grass, it was practically impossible for the company to observe the enemy. On the other hand, Company E was on bare and open ground which exposed it to machine gun and mortar fire from Hill 918. Both companies also came under long-range machine gun fire from the vicinity of Kang Dagit, northeast of Hill 918. It was impractical to attempt an envelopment to the right, since the flank of Company E rested on a deep ravine which ran to the bed of the Bagan River. An envelopment to the left would have necessitated going down the hill, circling behind Company G, and attacking east from the positions of the 1st Battalion. Because of these unfavorable conditions, Companies E and F with their wounded withdrew to make a line with Company G.[63]