On the evening of 24 July a 50-strong PVA force probed 2 RAR's forward outposts after dark, attacking C Company on Hill 121 and surrounding a bunker on the left flank, while the Marines had a similar contact on the left flank.
A forward Australian standing patrol from D Company subsequently clashed heavily with the PVA probe, losing five wounded before directing tank and artillery fire which dispersed their attackers.
These attacks had been preceded by heavy artillery and mortar fire, with the PVA subjecting C and D Companies, 2 RAR and the 2 RAR Mortar Platoon to a heavy bombardment.
Waves of PVA attacked the Australians at 20:50, penetrating between C Company on Hill 121 and the nearest Marines on Hill 111, before being turned back amidst the driving rain.
A further attack followed another barrage at 23:25, but was again repelled and faltered before reaching the wire during fierce fighting with grenades and small-arms, with the assault failing largely due to the weight of defensive artillery fire.
More than 2,000 PVA mortar and artillery rounds fell on the Australian positions during the night.
Two Australians were killed and 14 wounded during the night attack which was later estimated to have been made by a PVA regiment of up to 4,000 men.
The defenders were soaking wet and exhausted, but had held their positions.
Yet despite the weight of the PVA attack against the Australians their main objective had been Hill 119, another strong point in the American sector 500 metres (550 yd) to the south-west of Hill 111, known as Boulder City, held by the 7th Marine Regiment.

The PVA engaged the Marines on Boulder City with preparatory fire from mortars and artillery at 19:30.
Ten minutes later PVA troops were observed massing for an assault north-west of the Berlin feature and were subsequently shelled by the Americans.
At 20:30 the PVA probed the right flank held by the 3rd Battalion, 7th Marines, first striking Hill 111 and then at Boulder City.
After infiltrating forward, the PVA had hid in the paddy fields immediately in front of the American positions during the barrage, and had then rapidly assaulted as soon as the artillery had lifted.
The attack coincided with the ongoing relief in place of the defenders by the 1st Marine Regiment under the command of Colonel Wallace M. Nelson, and it subsequently succeeded in temporarily penetrating the American positions on Hill 111.
Yet the PVA main effort fell on Boulder City, and two battalions subsequently succeeded in occupying a portion of the American trench line.
From these positions the PVA threatened to cut-off Company G, 3rd Battalion, 1st Marines on Hill 119, repeatedly assaulting the Berlin Gate feature on the company's left flank and the East Berlin Gate on its right in an effort to exploit their gains.
Throughout the fighting the Marines were strongly supported by heavy mortar, artillery and tank fire; however, due to the prevailing weather conditions no spotter aircraft were able to fly during the night which limited the effectiveness of the indirect fire available to them.

In support of the Marines on Hill 111 at 21:10 Wilton had ordered one company of the 1 DLI to occupy a reserve position on the left of 2 RAR, in the rear of the 1st Marine Division where they ultimately remained for the rest of the evening.
A reserve company from 3 RAR was also embussed in order to be ready to respond to any emergency.
The Americans eventually drove off the PVA probes after their artillery broke up the attack, but not before they were forced to abandon some of their forward positions.
With the attack likely only a diversionary effort, by 21:20 the bulk of the PVA had begun to withdraw from Hill 111.
Meanwhile, the fighting on Hill 119 continued.
A heavy bombardment fell on the American positions at 21:00, followed by a second assault on Hill 119 by two PVA companies which succeeded in penetrating the Marine perimeter.
Hand-to-hand combat developed across the forward trenches and in the ensuing fighting Company G was reduced to half-strength, while their ammunition began to run low.
On the evening of 24 July a 50-strong PVA force probed 2 RAR's forward outposts after dark, attacking C Company on Hill 121 and surrounding a bunker on the left flank, while the Marines had a similar contact on the left flank. A forward Australian standing patrol from D Company subsequently clashed heavily with the PVA probe, losing five wounded before directing tank and artillery fire which dispersed their attackers. These attacks had been preceded by heavy artillery and mortar fire, with the PVA subjecting C and D Companies, 2 RAR and the 2 RAR Mortar Platoon to a heavy bombardment. Waves of PVA attacked the Australians at 20:50, penetrating between C Company on Hill 121 and the nearest Marines on Hill 111, before being turned back amidst the driving rain. A further attack followed another barrage at 23:25, but was again repelled and faltered before reaching the wire during fierce fighting with grenades and small-arms, with the assault failing largely due to the weight of defensive artillery fire. More than 2,000 PVA mortar and artillery rounds fell on the Australian positions during the night. Two Australians were killed and 14 wounded during the night attack which was later estimated to have been made by a PVA regiment of up to 4,000 men. The defenders were soaking wet and exhausted, but had held their positions. Yet despite the weight of the PVA attack against the Australians their main objective had been Hill 119, another strong point in the American sector 500 metres (550 yd) to the south-west of Hill 111, known as Boulder City, held by the 7th Marine Regiment.
The PVA engaged the Marines on Boulder City with preparatory fire from mortars and artillery at 19:30. Ten minutes later PVA troops were observed massing for an assault north-west of the Berlin feature and were subsequently shelled by the Americans. At 20:30 the PVA probed the right flank held by the 3rd Battalion, 7th Marines, first striking Hill 111 and then at Boulder City. After infiltrating forward, the PVA had hid in the paddy fields immediately in front of the American positions during the barrage, and had then rapidly assaulted as soon as the artillery had lifted. The attack coincided with the ongoing relief in place of the defenders by the 1st Marine Regiment under the command of Colonel Wallace M. Nelson, and it subsequently succeeded in temporarily penetrating the American positions on Hill 111. Yet the PVA main effort fell on Boulder City, and two battalions subsequently succeeded in occupying a portion of the American trench line. From these positions the PVA threatened to cut-off Company G, 3rd Battalion, 1st Marines on Hill 119, repeatedly assaulting the Berlin Gate feature on the company's left flank and the East Berlin Gate on its right in an effort to exploit their gains. Throughout the fighting the Marines were strongly supported by heavy mortar, artillery and tank fire; however, due to the prevailing weather conditions no spotter aircraft were able to fly during the night which limited the effectiveness of the indirect fire available to them.
In support of the Marines on Hill 111 at 21:10 Wilton had ordered one company of the 1 DLI to occupy a reserve position on the left of 2 RAR, in the rear of the 1st Marine Division where they ultimately remained for the rest of the evening. A reserve company from 3 RAR was also embussed in order to be ready to respond to any emergency. The Americans eventually drove off the PVA probes after their artillery broke up the attack, but not before they were forced to abandon some of their forward positions. With the attack likely only a diversionary effort, by 21:20 the bulk of the PVA had begun to withdraw from Hill 111. Meanwhile, the fighting on Hill 119 continued. A heavy bombardment fell on the American positions at 21:00, followed by a second assault on Hill 119 by two PVA companies which succeeded in penetrating the Marine perimeter. Hand-to-hand combat developed across the forward trenches and in the ensuing fighting Company G was reduced to half-strength, while their ammunition began to run low. 
Battle of the Samichon River