The 2/14th Infantry Battalion, a Victorian unit, along with the 54th Battery of the 2/4th Field Regiment, finally flew in to Kaiapit from Nadzab on 25 September, but the first elements of the 25th Infantry Brigade did not arrive for another two days.
Part of the problem was that the Fifth Air Force restricted landings at Kaiapit to between 09:00 and 15:30 the previous day in order to conserve fighters.
Vasey met with Iven Mackay (commander of New Guinea Force), Herring, Frank Berryman (Mackay's chief of staff), George C. Kenney (commander of Allied Air Forces) and Arthur S. Carpender (commander of Allied Naval Forces) in Port Moresby on 26 September.
Vasey was informed that the construction of the Markham Valley Road from Lae to Nadzab and operations around Finschhafen had priority, and his 18th Infantry Brigade would not be flown in except in the event of an emergency.
The pause allowed a native labour force to be collected at Kaiapit.
Some 300 were flown in from Nadzab, and ANGAU hired local labour to bring the total labour force to about 600.

There was mounting evidence that the Japanese were retreating and not advancing.
On 26 September, Crombie reported that Rumu was unoccupied.
The following day, patrols from the 2/6th Independent Company and B Company, Papuan Infantry Battalion reported that Narawapum was also deserted.
That evening, Vasey signalled Dougherty, authorising an advance on Marawasa "with all speed".
The 21st Infantry Brigade set out accompanied by the Papuan company, and detachments of the 2/6th Field Ambulance and 2/4th Field Regiment.
Six jeeps hauled rations, four carried the brigade headquarters and signals, three brought the 2/6th Field Ambulance, and two towed 25 pounders.

On 28 September, two companies of the 2/16th crossed the Umi.
After dusk, the rest of the 21st Infantry Brigade followed, crossing in five rubber rafts.
The jeeps and light guns were dragged across the Umi, leaving three behind to form a shuttle service that moved stores from Kaiapit.
They were taken across the river and thence to a dump at Sagarak.
By the morning of 30 September, all the stores were across the river.
The track became impassable about 2 miles (3.2 km) beyond Sagerak, requiring some work to be done to improve it.
The airstrip at Sagerak was put to use, with four more jeeps and trailers, and some supplies flown in.
Vasey also flew in, bringing new, written orders for an advance on Gusap.
By this time, Herring knew that the rest of the Japanese 20th Division was on the Rai Coast and not in the Marawasa area, so Vasey was opposed only by its 78th Infantry Regiment.

Bena Bena was garrisoned by the 2/2nd and 2/7th Independent Companies.
These patrolled ahead of the 21st Infantry Brigade's advance.
On 28 September, a heavily armed patrol from the 2/7th Independent Company under Captain D. St A. Dexter ambushed about 60 Japanese soldiers near Kesawai in the Ramu Valley, inflicting severe casualties on the Japanese.

Although native porters were engaged to bring rations forward to the troops, the 2/16th and 2/27th advanced so fast on 1 October that stores had to be dropped by air.
The drop was made at 19:00 but owing to poor light, the long grass and inadequate marking of the drop zone, only half the stores were retrieved.
The following day they reached the juncture of the Ramu and Gusap Rivers.
The 2/14th Infantry Battalion, a Victorian unit, along with the 54th Battery of the 2/4th Field Regiment, finally flew in to Kaiapit from Nadzab on 25 September, but the first elements of the 25th Infantry Brigade did not arrive for another two days. Part of the problem was that the Fifth Air Force restricted landings at Kaiapit to between 09:00 and 15:30 the previous day in order to conserve fighters. Vasey met with Iven Mackay (commander of New Guinea Force), Herring, Frank Berryman (Mackay's chief of staff), George C. Kenney (commander of Allied Air Forces) and Arthur S. Carpender (commander of Allied Naval Forces) in Port Moresby on 26 September. Vasey was informed that the construction of the Markham Valley Road from Lae to Nadzab and operations around Finschhafen had priority, and his 18th Infantry Brigade would not be flown in except in the event of an emergency. The pause allowed a native labour force to be collected at Kaiapit. Some 300 were flown in from Nadzab, and ANGAU hired local labour to bring the total labour force to about 600.
There was mounting evidence that the Japanese were retreating and not advancing. On 26 September, Crombie reported that Rumu was unoccupied. The following day, patrols from the 2/6th Independent Company and B Company, Papuan Infantry Battalion reported that Narawapum was also deserted. That evening, Vasey signalled Dougherty, authorising an advance on Marawasa "with all speed". The 21st Infantry Brigade set out accompanied by the Papuan company, and detachments of the 2/6th Field Ambulance and 2/4th Field Regiment. Six jeeps hauled rations, four carried the brigade headquarters and signals, three brought the 2/6th Field Ambulance, and two towed 25 pounders.
On 28 September, two companies of the 2/16th crossed the Umi. After dusk, the rest of the 21st Infantry Brigade followed, crossing in five rubber rafts. The jeeps and light guns were dragged across the Umi, leaving three behind to form a shuttle service that moved stores from Kaiapit. They were taken across the river and thence to a dump at Sagarak. By the morning of 30 September, all the stores were across the river. The track became impassable about 2 miles (3.2 km) beyond Sagerak, requiring some work to be done to improve it. The airstrip at Sagerak was put to use, with four more jeeps and trailers, and some supplies flown in. Vasey also flew in, bringing new, written orders for an advance on Gusap. By this time, Herring knew that the rest of the Japanese 20th Division was on the Rai Coast and not in the Marawasa area, so Vasey was opposed only by its 78th Infantry Regiment.
Bena Bena was garrisoned by the 2/2nd and 2/7th Independent Companies. These patrolled ahead of the 21st Infantry Brigade's advance. On 28 September, a heavily armed patrol from the 2/7th Independent Company under Captain D. St A. Dexter ambushed about 60 Japanese soldiers near Kesawai in the Ramu Valley, inflicting severe casualties on the Japanese.
Although native porters were engaged to bring rations forward to the troops, the 2/16th and 2/27th advanced so fast on 1 October that stores had to be dropped by air. The drop was made at 19:00 but owing to poor light, the long grass and inadequate marking of the drop zone, only half the stores were retrieved. The following day they reached the juncture of the Ramu and Gusap Rivers.
Battle of Dumpu