Day 1 - December 12th, 1942
Soviet troops on the southern flank find themselves under intense artillery bombardment on the dawn of December 12th. Within minutes, German infantry and armoured vehicles cross the lines and attack. STAVKA has not anticipated the Germans to be able to mount a counterattack so quickly, and despite correctly predicting the direction, Soviet troops are cought by surprise as the 4th Panzer Army's LVII Panzer Corps cuts into the Soviet 51st Army.
To the east, the 23rd Panzer Division outflanks and attacks the 38th Motor Rifle Brigade's position on Hill 169, capturing Talochkin in the process. Barely managing to hold onto its position, the Soviet unit loses over two-thirds of its strength. The 6th Panzer Division and 15th Luftwaffe Field Division simultaneously strike at the center of the 4th Cavalry Corps' line; though the Soviet line is breached, the defenders manage to retreat in good order. German engineers set up bridges across the Don river across from Krasnoarsky, allowing the 17th Panzer Division to cross the river and capture the town. German units advance up to 10 kilometers.
With the first line breached and outflanked, the 4th Cavalry Corps is ordered to abandon its positions. Because of the disorganization caused by the German attack, most units are unable to make it behind the Aksay river, which will serve as the next defensive position, so an ad-hoc line is created south of the river. Due to the lack of prepared entrenchments, however, this position will not be able to hold on for long. The troops of the 13th Mechanized Corps, behind the lines and available as an immediate reserve, are ordered to dig in behind the river while the 4th Cavalry Corps delays the enemy advance.
To the north, Soviet units of the 51st Army Rifle Corps and 4th Mechanized Corps successfully attack small German units still on the left bank of the Don. After this area is secured, these units will be moved southwards to block the German offensive.
Other areas do not see much action. German units occupy the southern half of Bolshin with no resistance and contact the Soviet defenses across the Chir river. Some movement is spotted inside the pocket, but there appear to be no attempt by the Sixth Army to break out. More worrying, large amounts of troops and equipment are spotted to be moving by rail from Pavlomaya towards the southern Chir salient. These units possibly belong to the German 19th Panzer Division, but that is not certain.
