However, after days of heavy fighting, Polish units were reduced to 30-50% of their original strength (except for the Armoured Brigade), lacking batteries, antitank ammunition and controllers.

Furthermore, communication between separate divisions was strong, and they had no lots of support, which was a huge advantage, as they had an idea about movements and location of German forces.

These plans, however, were quickly changed, after the Germans destroyed key Polish unit, 21st Mountain Division near the village of Dzikowiec, on 15-16 September, killing general Józef Kustroń.

General Piskor, realizing that German forces were stronger than he had thought, decided to act quickly, without waiting for all his divisions to concentrate.

After a series of chaotic skirmishes, with number of killed and wounded growing, and ammunition shrinking, general Piskor decided to surrender.

Meanwhile, Operational Group "Boruta" (named after General Mieczysław Boruta-Spiechowicz), which was part of Army Kraków, separated from main Polish forces and marched towards Narol.

[6] The second phase (also known as the Second Battle of Tomaszów Lubelski) involved Polish units from the so-called Northern Front - remaining elements of Army Lublin, Army Modlin and Operational Groups Wyszków, Narew and Nowogródzka Cavalry Brigade under generals Emil Krukowicz-Przedrzymirski and Stefan Dąb-Biernacki.

Northern Front forces marched southwards from the area of Chełm in two columns, towards Zamość, which Dąb-Biernacki decided to attack.

In the evening of 22 September cavalry of general Władysław Anders attacked, capturing Krasnystaw, and then reaching Sambor.