Following the fighting on 31 August, the Japanese forces ashore had reported the situation to their headquarters at Rabaul.
In response, plans were made to send the Aoba Detachment, which comprised the Army's 4th Infantry Regiment and an artillery company, to Rabi to complete the capture of the airfield.
However, they were not scheduled to arrive until 11 September and so it was planned in the meantime to reinforce Yano's men with 130 men from the 5th Yokosuka SNLF.
An abortive attempt was made to land these troops on 2 September and then again on 4 September.
By that time, however, as further reports were received by the Japanese headquarters, it became apparent that Yano's troops would not be able to hold out until the Aoba Detachment could arrive.
As a result, on 5 September, the Japanese high command ordered a withdrawal.
This was carried out from the sea that evening.

Meanwhile, six Beauforts of No.
100 Squadron RAAF had arrived at Milne Bay on 5 September.
An additional three Beaufighters of No.
30 Squadron RAAF, the first to operate this aircraft, joined them the following day.
The Beauforts were tasked with providing additional support against further landings and undertaking anti-shipping missions.
On 6 September, the Allied offensive reached the main camp of the Japanese landing force, fighting a number of minor actions against small groups that had been left behind after the evacuation.

Shortly after ten on the evening of 6 September, as the freighter Anshun was continuing unloading cargo under her lights, the port came under fire from the Japanese cruiser Tenryū and the destroyer Arashi with Anshun receiving about ten hits from the cruiser and rolling onto her side.
The Japanese ships also shelled shore positions at Gili Gili and Waga Waga and illuminated, but did not fire on, the hospital ship Manunda which was displaying her hospital ship colours and lights.
The next night, two Japanese warships – a cruiser and a destroyer – bombarded Australian positions causing a number of casualties for 15 minutes before leaving the bay; it would be their final act in the battle.
During the mopping up operations that followed, patrols by Australian troops tracked down and killed a number of Japanese troops who were attempting to trek overland to Buna.

The 350 Japanese troops who had been stranded on Goodenough Island after their barges were destroyed on 24 August were not rescued until late October.
An attempt to evacuate the force on 11 September ended in failure when the two destroyers assigned to this mission were attacked by USAAF aircraft, resulting in the loss of Yayoi.
Two further attempts to rescue the force on 13 and 22 September were unsuccessful, though supplies were air-dropped on Goodenough Island.
A submarine landed further supplies and evacuated 50 sick personnel on 3 and 13 October.
As part of the preparations for the attack on Buna and Gona, the 2/12th Infantry Battalion was assigned responsibility for securing Goodenough Island on 19 October.
The battalion landed on the island three days later.
A series of small engagements on 23 and 24 October cost the Australian force 13 killed and 19 wounded, and the Japanese suffered 20 killed and 15 wounded.
The remaining Japanese troops were evacuated by two barges to nearby Fergusson Island on the night of 24 October, and the light cruiser Tenryū rescued them two days later.
After securing the island, the 2/12th began work on building Vivigani Airfield on its east coast.
Following the fighting on 31 August, the Japanese forces ashore had reported the situation to their headquarters at Rabaul. In response, plans were made to send the Aoba Detachment, which comprised the Army's 4th Infantry Regiment and an artillery company, to Rabi to complete the capture of the airfield. However, they were not scheduled to arrive until 11 September and so it was planned in the meantime to reinforce Yano's men with 130 men from the 5th Yokosuka SNLF. An abortive attempt was made to land these troops on 2 September and then again on 4 September. By that time, however, as further reports were received by the Japanese headquarters, it became apparent that Yano's troops would not be able to hold out until the Aoba Detachment could arrive. As a result, on 5 September, the Japanese high command ordered a withdrawal. This was carried out from the sea that evening.
Meanwhile, six Beauforts of No. 100 Squadron RAAF had arrived at Milne Bay on 5 September. An additional three Beaufighters of No. 30 Squadron RAAF, the first to operate this aircraft, joined them the following day. The Beauforts were tasked with providing additional support against further landings and undertaking anti-shipping missions. On 6 September, the Allied offensive reached the main camp of the Japanese landing force, fighting a number of minor actions against small groups that had been left behind after the evacuation.
Shortly after ten on the evening of 6 September, as the freighter Anshun was continuing unloading cargo under her lights, the port came under fire from the Japanese cruiser Tenryū and the destroyer Arashi with Anshun receiving about ten hits from the cruiser and rolling onto her side. The Japanese ships also shelled shore positions at Gili Gili and Waga Waga and illuminated, but did not fire on, the hospital ship Manunda which was displaying her hospital ship colours and lights. The next night, two Japanese warships – a cruiser and a destroyer – bombarded Australian positions causing a number of casualties for 15 minutes before leaving the bay; it would be their final act in the battle. During the mopping up operations that followed, patrols by Australian troops tracked down and killed a number of Japanese troops who were attempting to trek overland to Buna.
The 350 Japanese troops who had been stranded on Goodenough Island after their barges were destroyed on 24 August were not rescued until late October. An attempt to evacuate the force on 11 September ended in failure when the two destroyers assigned to this mission were attacked by USAAF aircraft, resulting in the loss of Yayoi. Two further attempts to rescue the force on 13 and 22 September were unsuccessful, though supplies were air-dropped on Goodenough Island. A submarine landed further supplies and evacuated 50 sick personnel on 3 and 13 October. As part of the preparations for the attack on Buna and Gona, the 2/12th Infantry Battalion was assigned responsibility for securing Goodenough Island on 19 October. The battalion landed on the island three days later. A series of small engagements on 23 and 24 October cost the Australian force 13 killed and 19 wounded, and the Japanese suffered 20 killed and 15 wounded. The remaining Japanese troops were evacuated by two barges to nearby Fergusson Island on the night of 24 October, and the light cruiser Tenryū rescued them two days later. After securing the island, the 2/12th began work on building Vivigani Airfield on its east coast.
Battle of Milne Bay