Meanwhile , the previous day , 3 May , the 57th / 60th Infantry Battalion had begun operating along the parallel Commando Road to the north . Here they had a number of encounters and suffered casualties due to their inexperience in patrolling , which resulted in them being ambushed . They also kept up a steady advance and eventually beat the main force in reaching , and crossing the river , arriving there on 6 May . On 5 May , along the Buin Road , the 24th Infantry Battalion had pressed forward again . Advancing with a tank troop in support , they came up against a concealed field gun defended by approximately 100 Japanese . After the lead Matilda 's machine gun jammed , the field gun opened fire on it , damaging it and wounding its crew . Moving around the stricken tank , the second Matilda , armed with a howitzer , opened fire and destroyed the field gun before sweeping the Japanese defenders from the position . That night , the Japanese artillery opened up on the Australian position with a heavy barrage , and the following morning put in a company @-@ sized counter @-@ attack . The fighting lasted for over two @-@ and @-@ a @-@ half hours , but when it was over the Australians remained in possession of the position having repulsed the attack . In doing so , they suffered one killed and nine wounded , while the attacking Japanese had suffered heavily , losing 58 men killed . It was the biggest loss since the action at Slater 's Knoll and it spelt the end of their attempt to defend the Hongorai .