5th Division's situation deteriorates rapidly as still more Warsaw Pact forces are brought to bear.
At dawn, the 256th Brigade in Łask is hit from the east and northeast by strong, fully-mechanized forces and the brigade HQ is overrun. Still short of fuel, most of the brigade's tanks fought and died where they sat. Surviving personnel broke out through the woods to the southwest. The attackers were identified as the Soviet 124th Motorized Rifle Division, another component of the 4th Guards Tank Army. While the 256th Brigade was being overrun, elements of the Soviet 21st Motorized Rifle Division appeared behind the 4-12 Cavalry's positions at Sieradz, having marched north from Złoczew. The 21st MRD was yet another division of the 4th Guards Tank Army and the 4-12 Cavalry, down to fewer than 200 troopers, withdrew northwest towards Kalisz. 7th Engineers completed the bridge at Uniejów in the morning and 1st Brigade began crossing their remaining heavy equipment. At the same time, they were forced to repel cautious probing attacks by Polish cavalry from the east. By late afternoon, the 1-40 Armored was repelling probing attacks of dismounted infantry from Pleszew, to the west, and Ostrów, to the southwest. That evening, the division commander ordered all units to blow any remaining bridges over the Warta and consolidate at Kalisz. Divisional elements at Konin, Koło, and Uniejów do just that but with the 4-12 Cavalry having been forced to abandon Sieradz, the bridge there was firmly in enemy hands.