When the Soviet 4th Tank Corps entered the breakthrough, General von Weix finally decided that the time had come to dispatch the armored reserve. At 10:10 a.m. (12:10 Soviet time), Weix ordered Lieutenant General Heim to command the 48th Panzer Corps to launch a counterattack. However, in the face of the Soviet army attacking from three directions, Weix could not find the main direction of attack. He considered the direction of Kretzkaya (the breakthrough point of the Soviet 4th Tank Army) as the focus, but ignored the Soviet 5th Tank Army on the west side of the Soviet 21st Army (Serafimovich area).
The Soviet 5th Tank Army was more powerful than the 4th Tank Army. Commanded by Lieutenant General Romanenko, the army group consisted of 6 infantry divisions and 1 cavalry corps, as well as the 1st and 26th Tank Corps, the 8th Tank Brigade of the Guards, the 8th Motorcycle Regiment, and the 510th and 511th Independent Tank Battalions. The 5th Tank Army spread out on a 35 km wide frontal area with the following strengths:
There were 104,000 soldiers (90,000 in combat units). There were 378 tanks (including 60 heavy tanks). It was also equipped with 1502 guns and mortars of 76 mm or more, 197 45 mm anti-tank guns, 156 anti-aircraft guns and 62 rocket launchers.
The 5th Tank Army's Rapid Corps (1st and 26th Tank Corps) entered the breakthrough some later than the 21st Army's Rapid Corps. Although as early as 7-9 a.m., the tank corps was under the cover of thick fog, driving from the standby area to about 8-10 kilometers in front of the enemy. The 26th Tank Corps had a total of 161 tanks. Of these, 55 tanks (under the 216th Tank Brigade) were assigned to the 124th Infantry Division of the First Echelon. Only the 157th and 19th Tank Brigades were used as a rapid force, while the 1st Tank Corps had 136 tanks, while the entire Rapid Army had 242 tanks.