General Sasaki initially took advantage of the disorder on the American side. The Japanese learned to apply close assault tactics against American tanks, rendering armor even less effective in the jungle than usual. Meanwhile, the inexperienced, hungry and fatigued US soldiers' nerves began to fray and they began to lose their fire discipline. On the night of 17 July, the Japanese launched a strong counterattack and succeeded in overrunning the command post of the 43rd Division near Zanana. Eventually, however, Sasaki's troops became sick and exhausted; also, he had lost communications with Rabaul. US forces, bolstered by the arrival of the 37th Infantry Division, subsequently launched a corps-level offensive under Griswold aimed at capturing Munda Point. Sasaki ordered a retreat from the Munda area on 3 August. General Griswold had his men sweep around Munda to the northwest and on 5 August plastered the remaining Japanese with artillery fire. That day, the Americans moved unopposed into Munda, finally achieving the campaign's most important goal.