On 23 July, the main body of Army Group B started its advance toward the Don. The Germans met with increasing Soviet resistance from the new Stalingrad Front, with the 62nd and 64th Soviet Armies. On 26 July, XIV Panzer Corps broke through and reached the Don, where the new First and Fourth Tank Armies conducted several futile counter-attacks by inexperienced troops. In the south, Fourth Panzer Army made better progress against 51st Army. After crossing the Don, the Germans advanced on Kotelnikovo, reaching the town by 2 August. Soviet resistance convinced Paulus that Sixth Army was not strong enough to cross the Don by itself, so he waited for Fourth Panzer Army to fight its way north. On 4 August, the Germans were still from Stalingrad.