In the effect of a three-day-long struggle for the control of the city of Grodno (modern Hrodna, Belarus), the town was captured by Russian forces, despite repeated counter-attacks by Polish infantry, tanks and armoured trains.

Instead, the Polish defences were manned by sentry guards, mobilised railway workers, students of a local NCO school and remnants of various units defeated near Wilno a couple of days before.

[8][9] In the area of Grodno two Polish divisions broke contact with the enemy and successfully withdrew to a 50 kilometre line of dilapidated fortifications surrounding the city.

[1] His mistakes could not be corrected by his superior, General Gustaw Zygadłowicz, the commanding officer of the Polish First Army as he was stranded in an isolated village following his staff car's malfunction and lost contact with his troops for two days.

[11] Furthermore, on 18 July the Polish Cipher Bureau intercepted a Russian report claiming that the 3rd Cavalry Corps driving towards Grodno was exhausted and that its horses were in need of rest.

[5] Gen. Mokrzecki, having committed all his infantry reserves to the fight, ordered the 2nd tank platoon under 2nd Lt. Bohdan Jeżewski to counter-attack towards the village of Grandzicze, directly to the north of the town.

[3] Later that day a second wave of Russian forces arrived, having routed two reserve squadrons of Polish cavalry operating to the east of Grodno.

However, when the Russian 10th Cavalry Division charged towards the rail road circling the town from the east, they were fired upon by tanks of the 1st company, still loaded on flatcars and operating as an improvised armoured train.

[3] General Mokrzecki panicked,[1] and ordered all Polish troops withdrawn from the eastern part of the town back to the city centre, to the vicinity of the train station and the bridges across Neman River.

[12] After the successful retreat to the south-western bank of the river, only the 3rd tank platoon of 2nd company and some isolated Polish infantry forces were left in the city.

Most of the town was already in Russian hands and around 18:00 the Cossacks of the 2nd Cavalry Brigade assaulted the isolated Polish position from the back, through the narrow streets of down-town Grodno.

The column started moving slowly towards friendly positions, with Russians trying to assault it from the sides in the narrow streets of the city centre.

In his memoir, Hayk Bzhishkyan recalled that the fights for Grodno cost him "500 killed and wounded, 400 horses and seven days of priceless time".

Several post-war authors called the Polish defence of Grodno on 19 July "mediocre at best",[1][12] and argued that the officers suffered from a "psychosis of disaster and retreat".