By late afternoon on 23 February 1 RAR had adopted a position in all-round defence in the vicinity of the Suoi Bong Trang, a major creek to the west of the US 1st Brigade's headquarters, while the US engineers had moved into a new defensive position inside the Australian perimeter.
Meanwhile, alerted by the Australians, a platoon of M48 Patton tanks from Troop B, 1st Squadron, US 4th Cavalry Regiment and a second 105-millimetre (4.1 in) howitzer field battery from 1st Battalion, US 5th Artillery Regiment had been moved in to defend the Brigade Headquarters.
1st Battalion, US 26th Infantry Regiment—under the command of Lieutenant Colonel Y.Y. Phillips—returned from the field and also deployed in defence by last light, augmenting Company B, 1st Battalion, US 28th Infantry Regiment.
Additional ammunition was also brought forward, in anticipation of a likely Viet Cong attack.

At 22:00, soldiers from B Company, 1 RAR, occupying the western sector of the Australian perimeter noticed lights 250 metres (270 yd) to their front.
McFarlane subsequently requested artillery and mortar fire to target the location, but the request was declined by Preece.
Meanwhile, a small Australian standing patrol that had deployed forward of the company main defensive position under the command of Private Walter Brunalli, observed the lights moving closer, east of the US 1st Brigade's headquarters.
Two tanks had been positioned forward of the American positions, with a squad of infantry on the eastern approaches, and by midnight they had also reported sounds of movement and intermittent flashes of light through the trees.
In the early morning of 24 February, just after midnight, sporadic firing was heard throughout the area.
The forward American listening posts had detected small groups of Viet Cong moving outside the perimeter, killing two and forcing the remainder to withdraw into the darkness after one of the sentries opened fire.
Glotzbach waited for the Viet Cong main effort, however, and withheld the bulk of the firepower at his disposal.

With their defences alerted, the Americans and Australians "stood to" for the next 45 minutes.
The battle began at 01:45 with a heavy barrage of Viet Cong mortar and small arms fire.
The Americans responded with small arms, machine-guns, tank fire, mortars and artillery and over the next hour the firing grew in intensity until, at 03:00, the Viet Cong switched their fires to the north-west side of the American perimeter, augmenting their barrage with recoilless rifles.
Glotzbach expected a full-scale ground assault, but the Viet Cong had been held back by the weight of American firepower, with heavy artillery including 8-inch (200 mm) and 175-millimetre (6.9 in) howitzers firing in support from Phuoc Vinh, in addition to the defenders' own artillery, which was now firing over open sights after lowering their tubes to fire directly at the Viet Cong positions.
In total eight field batteries were available.
Elsewhere, the Australian standing patrol had remained in position despite the proximity of the Viet Cong, and with the Americans pouring massive fire into the area they were soon caught in the crossfire.
Brunalli was subsequently wounded in the arm.

Although the Australian position was not the focus of the attack, it too soon came under attack from 60-millimetre (2.4 in) mortars, killing an American sapper.
With the base plate positioned between the Australians and the US 1st Brigade's headquarters there was initial confusion over the source of the rounds, and both Gloztbach and Preece accused the other of firing on their positions.
However, after US aircraft arrived overhead to illuminate the battlefield the Australians were able to join the fighting, and they began firing at masses of Viet Cong who had become disorientated and were milling around on the battlefield.
Earlier, a number of Australian ambushes had intercepted Viet Cong pathfinder groups and this had largely prevented the communists from conducting a final reconnaissance of their objectives.
Unaware of the newly strengthened defences, they had
By late afternoon on 23 February 1 RAR had adopted a position in all-round defence in the vicinity of the Suoi Bong Trang, a major creek to the west of the US 1st Brigade's headquarters, while the US engineers had moved into a new defensive position inside the Australian perimeter. Meanwhile, alerted by the Australians, a platoon of M48 Patton tanks from Troop B, 1st Squadron, US 4th Cavalry Regiment and a second 105-millimetre (4.1 in) howitzer field battery from 1st Battalion, US 5th Artillery Regiment had been moved in to defend the Brigade Headquarters. 1st Battalion, US 26th Infantry Regiment—under the command of Lieutenant Colonel Y.Y. Phillips—returned from the field and also deployed in defence by last light, augmenting Company B, 1st Battalion, US 28th Infantry Regiment. Additional ammunition was also brought forward, in anticipation of a likely Viet Cong attack.
At 22:00, soldiers from B Company, 1 RAR, occupying the western sector of the Australian perimeter noticed lights 250 metres (270 yd) to their front. McFarlane subsequently requested artillery and mortar fire to target the location, but the request was declined by Preece. Meanwhile, a small Australian standing patrol that had deployed forward of the company main defensive position under the command of Private Walter Brunalli, observed the lights moving closer, east of the US 1st Brigade's headquarters. Two tanks had been positioned forward of the American positions, with a squad of infantry on the eastern approaches, and by midnight they had also reported sounds of movement and intermittent flashes of light through the trees. In the early morning of 24 February, just after midnight, sporadic firing was heard throughout the area. The forward American listening posts had detected small groups of Viet Cong moving outside the perimeter, killing two and forcing the remainder to withdraw into the darkness after one of the sentries opened fire. Glotzbach waited for the Viet Cong main effort, however, and withheld the bulk of the firepower at his disposal.
With their defences alerted, the Americans and Australians "stood to" for the next 45 minutes. The battle began at 01:45 with a heavy barrage of Viet Cong mortar and small arms fire. The Americans responded with small arms, machine-guns, tank fire, mortars and artillery and over the next hour the firing grew in intensity until, at 03:00, the Viet Cong switched their fires to the north-west side of the American perimeter, augmenting their barrage with recoilless rifles. Glotzbach expected a full-scale ground assault, but the Viet Cong had been held back by the weight of American firepower, with heavy artillery including 8-inch (200 mm) and 175-millimetre (6.9 in) howitzers firing in support from Phuoc Vinh, in addition to the defenders' own artillery, which was now firing over open sights after lowering their tubes to fire directly at the Viet Cong positions. In total eight field batteries were available. Elsewhere, the Australian standing patrol had remained in position despite the proximity of the Viet Cong, and with the Americans pouring massive fire into the area they were soon caught in the crossfire. Brunalli was subsequently wounded in the arm.
Although the Australian position was not the focus of the attack, it too soon came under attack from 60-millimetre (2.4 in) mortars, killing an American sapper. With the base plate positioned between the Australians and the US 1st Brigade's headquarters there was initial confusion over the source of the rounds, and both Gloztbach and Preece accused the other of firing on their positions. However, after US aircraft arrived overhead to illuminate the battlefield the Australians were able to join the fighting, and they began firing at masses of Viet Cong who had become disorientated and were milling around on the battlefield. Earlier, a number of Australian ambushes had intercepted Viet Cong pathfinder groups and this had largely prevented the communists from conducting a final reconnaissance of their objectives. Unaware of the newly strengthened defences, they had 
Battle of Suoi Bong Trang