Russian troops continued to advance to the hinterland of East Prussia after they captured Fort Sternberg on August 10. Pu Jun occupied Lao Wei's position and cut off the road to Konigsberg. Aplak Sheen found that Pu Jun's position was very strong, so he sent troops to Ellenburg and made a detour from the south to Pu Jun's position. Russian troops arrived at the Fritz fritz pregl River, crossed the left bank and deployed in the woodland northeast of Stafford, yeager.
Aprasin thought that Pu Jun would not take the lead in the war, but would try his best to stop the Russian army from advancing on Ginsburg, so he began to lead the army to cut through the dense forest and run to Pu Jun's position along the only impassable road.
Lehwald saw through Aprasin's intention and took advantage of the weakness of Russian troops' slow action to launch a surprise attack. This caused the confusion of XinJun in Aplak. However, eager to take advantage of the favorable situation, Lewald neither organized reconnaissance nor launched a surprise attack on the established Russian flank, but launched an attack on its central part (to the 2nd Division in lopukhin). Pu Jun's first shock was repelled. However, the Russian army failed to resist another impact in this direction.
The Prussian infantry then circled behind the Second Division, forcing it to retreat. Pu Jun didn't let other Russian troops out of the forest to launch a battle formation and directly attack them. General Rumiantsev, who was in command of a brigade at that time, got the Russian army out of trouble. He made a bold determination to counterattack Pu Jun, led two regiments through the forest quickly, scattered at the edge of the forest, and made a surprise attack on Pu Jun's flank and rear. This makes it possible for the retreating Russian army to change its formation and make the battle process beneficial to itself.
Cossack on the Don, acting on the left, well done. They retreated in front of the Prussian cavalry and led Pu Jun under the fire of Russian infantry and artillery. When the Pu Jun cavalry was scattered and began to retreat, they turned to pursue. The rout of cavalry and the intensification of Russian attack led to the great retreat of Pu Jun. The Russian army won a hard-won victory, but it was an important victory. The Prussian army lost 5000 men and 29 cannons.
In this battle, the decisive factors for the Russian army to win were the soldiers' firmness, Rumiyantsev's maneuver, the correct determination of the direction and time of counterattack and the brave actions of many other commanders. Lehwald's troops retreated to the right bank of the Fritz fritz pregl River, thus clearing the way to Koenigsberg. But Aprasin didn't move forward.
After he occupied Fort Allen on September 5, he led the army to Tilsit on the grounds that the material security of the army was too poor. The real reason for his negative behavior is that he tried his best to please the royalists, because Crown Prince Peter Fedorovici (later Peter III), the patron of the royalists, opposed the war with Prussia.