On August 16, 1920, Polish forces defeat the Soviets at the Battle of Radzymin. Polish forces had set up a defensive position around the town of Radzymin as part of an effort to halt the advance of the Soviet Red Army before it could reach the Polish capital of Warsaw. A Soviet probing attack was repelled early in the morning of August 13, but a later assault caught the Polish troops by surprise and forced them from the city. However, the Poles remained outside of the city and planned to launch a counterattack to retake the city in the morning rather than retreat to another defensive line closer to Warsaw. Attacks and counterattacks through August 14 saw Radzymin remain in Soviet hands. On August 15, a Polish counter-offensive saw the town nearly encircled. As the Lithuanian-Belarusian Division of the Polish army moved to complete the encirclement, the Soviet occupiers retreated to avoid such a predicament and Radzymin once again fell into Polish hands. On August 16, a Soviet infantry assault reinforced by armored cars attempted to retake Radzymin but was ultimately repelled by the Polish defenders.

The Battle of Radzymin helped stall the Soviet advance and spared the city of Warsaw from capture. It (along with other battles in the defense of Warsaw) also bought the Polish military time to regroup and launch a counter-offensive which would push the Red Army back out of Poland and thus result in a Polish victory in the Soviet-Polish War.