 During the night of 18 November , the Austro @-@ Hungarians moved into position to carry out a further assault , which began the following morning . The Austro @-@ Hungarians ' main goal was to break through the defenses of the Serbian 2nd Army , concentrated primarily around Lazarevac , and to drive the Serbian 1st Army back towards the town of Gornji <unk> while simultaneously assaulting Serbian positions around the villages of Čovka and Vrače Brdo which threatened the Austro @-@ Hungarian flank . The Austro @-@ Hungarians gained a foothold at Vrače Brdo by the evening of 19 November , and seized higher ground from the Serbs further to the south . The Serbian 1st Army was forced to retreat the following day , giving the Austro @-@ Hungarians the ability to advance down the main routes leading to Kragujevac . Potiorek believed it was possible that Putnik was trying to lure the Austro @-@ Hungarians deeper into Serbia for the purpose of encircling them and then attacking their flanks , but correctly assessed that the Serbian Army was in no position to carry out such an attack . 
