Sixth Army advanced from the north via Kalach and Fourth Panzer Army came up from the south through Kotelnikovo. In the first few days, the XIV Panzer Corps opened a corridor between the main body of Sixth Army and the northern Stalingrad suburbs at the Volga. In the south, Soviet resistance repulsed the Fourth Panzer Army. On 29 August another attempt was made with Hoth turning his forces west directly through the center of 64th Army. The attack was unexpectedly successful and Fourth Panzer Army got behind 62nd and 64th Armies with the chance to encircle and cut off 62nd Army. Von Weichs ordered Sixth Army to complete the encirclement; a Soviet counter-attack held up the advance for three days and the Soviets escaped and retreated towards Stalingrad. The rapid German advance caused a slump in morale among the Soviet troops, who retreated in chaos, abandoning the outer defences of the city. After defeating the last Soviet counter-attacks, Sixth Army resumed its offensive on 2 September, linking up with Fourth Panzer Army the following day. On 12 September, the Germans entered Stalingrad.