After the battle, King Frederick II of Prussia was determined to force the Russians into a decisive engagement in order to prevent them joining up with the main Austrian army.

The Russians, however, shifted their forces into western Poland and marched westward toward the Oder river, a move that threatened the Prussian heartland, Brandenburg, and potentially Berlin itself.

[7] Upon orders from Empress Elizabeth, Saltykov moved on Prussia in a methodical advance beginning in June 1759.

By 19 July, he had reached the Silesian front near Züllichau (Sulechów), where Saltykov planned to rest his troops for a couple of days.

[8] Monitoring this from afar, and dissatisfied with Dohna's timidity in bringing Saltykov to battle, Frederick sent Carl Heinrich von Wedel to take command.

[8] On the same day as Wedel arrived, 20 July, Saltykov established himself astride the Prussian communication line at the Oder, strengthening his already formidable position.

General Heinrich von Manteuffel took six battalions and attacked on the artillery; initially they threw him back.

A contemporary participant maintained that Manteuffel succeeded in over-running the positions and took 40 pieces of cannon,[10] but there is no official evidence to support his statement.

When the superior Russian force countered, Prussian momentum faltered with the lack of a second column of timely reinforcement.

[3] In the last of these assaults, Moritz Franz Kasimir von Wobersnow led eight battalions and six squadrons from Züllichau against the Russian right wing.

[13] The loss at Kay laid open the road to the Oder river and by 28 July Saltykov's troops had reached Crossen.

Although Frederick had departed from Saxony in early July, and his brother had marched north at that time too, Daun feared that either of these armies would double back.

Eventually, Hadik and Loudon joined at Priebus (Przewóz), 40 km (25 mi) north of Görlitz, on 29 July.

On 3 August, the Russians occupied Frankfurt, while the main army camped outside the city on the east bank,[7] and began constructing field fortifications, in preparation for Frederick's eventual arrival.