Meanwhile, the 53rd Battalion and headquarters 30th Brigade under Brigadier Selwyn Porter were sent as reinforcements. Two battalions of the 2nd AIF's 21st Brigade under Brigadier Arnold Potts were following. A defensive position was established by Porter at Isurava with the 30th Brigade to be relieved by the 21st Brigade force. As Potts' lead battalion approached, he took command of the combined force to effect the relief. However, the Japanese advance overtook events and, from 26 to 31 August, a battle ensued in which four Japanese battalions were committed. The 53rd Battalion failed to secure the eastern flank and, with the Japanese taking a commanding position to the Australian front, ultimately forced an Australian withdrawal. The 21st Brigade then fought a series of engagements between 31 August and 5 September as it withdrew from Eora Village to Templeton's Crossing.