However, they failed to exploit their success as Augustus returned to Saxony soon thereafter to abide by the peace treaty, while Charles XII sent a new corps of 8,000 Swedes into Greater Poland.

[citation needed] When Potocki's Polish–Lithuanian forces were attacked by the Russians at Wielawa (or Piertkova) in mid-October, Mardefelt felt compelled to march to his support,[1] leaving behind a regiment in Poznań.

[1][4][16] The Swedish side overestimated the size of the coalition forces to at least 40,000, which is evident by a letter major general Ernst Detlof von Krassow sent to Charles XII after the battle.

[17] Augustus secretly sent letters to the Swedish major general Mardefelt, declaring that a peace treaty was concluded of which he expected further news from Charles XII, and that a battle should thus be avoided.

Augustus, not wanting to fight on the part of the coalition since he doubted any game-changing results could be won by defeating Mardefelt's small corps, tried to persuade him to retreat; because of his actions – or lack thereof – the battle began when it got dark.

[19] The Swedes captured the first line of defense of the Russians, but they quietly retreated with almost no losses, but this success was overestimated, the Swedish commander had already written a letter to Karl that he had defeated the coalition.

[25] The battle ended in a complete defeat for Sweden and its Polish-Lithuanian allies, with a major part of Greater Poland falling into the hands of the coalition forces as a result.

[28] It was, however, rendered moot when Charles XII exposed Augustus' ratification of the Altranstädt treaty, whereupon the latter gave in to obey by its terms and withdrew to Saxony by November.