Imita Ridge was the last major natural obstacle on the Kokoda Trail before the roadhead at Owers' Corner, and Port Moresby beyond. Having found the position at Ioribaiwa untenable, Brigadier Ken Eather, then commanding the Australian force on the Kokoda Trail, requested permission to withdraw to Imita Ridge on 16 September 1942. His reasoning was that a withdrawal to Imita Ridge would allow him to break contact with the Japanese, thereby regaining the initiative, and establish a stronger and more compact defensive position. This would then provide spare troops with which to mount strong patrols forward in preparation for a counter-offensive. The withdrawal had the added advantage that it shortened the Australians' supply line, while extending that of the Japanese.
The withdrawal to Imita Ridge began around 11am on 16 September. The first troops to move out were exhausted remnants of the 2/14th and 2/16th Battalions that had fought all the way back from Isurava. The battalions of Eather's own brigade followed during the afternoon. C Company of the 2/33rd Battalion was left behind on the track as a rearguard, ambushed the first of the pursuing Japanese when they appeared the next morning, and then pulled back. Patrols mounted from Imita Ridge in ensuing days discovered only scattered Japanese outposts forward of Ioribaiwa. A marked lack of activity on the behalf of the Japanese encouraged Eather to begin a cautious advance on 22 September and by nightfall on 27 September he was in a position to attack the Japanese at Ioribaiwa - the 2/25th Battalion would keep the Japanese focussed on their front, with the 2/33rd and 2/31st attacked from the right and left flanks, respectively. When the troops went forward the next morning the Japanese were found to have withdrawn during the night.
The withdrawal to Imita Ridge marked the turning point of the Kokoda Trail campaign. The Japanese force, its capacity to continue offensive operations already steadily declining due to its over stretched supply lines, had been ordered to conduct its own withdrawal and establish defensive positions on the north coast. Losses incurred against American forces on the island of Guadalcanal meant that offensive operations in Papua were postponed indefinitely.