On 28 December, the corps became part of the Southwestern Front. At the time it had 164 tanks, including 98 T-34s, 42 T-70s, and 24 T-60s. The corps unloaded at the Kalach rail station and from there its tank brigades conducted a 300 kilometer march to its positions for the forthcoming offensive. From 22 January it was under the operational control of the 6th Army. On 25 January, it became part of Group Popov. The corps fought in Operation Gallop, a Soviet counteroffensive after the Battle of Stalingrad, which attempted to encircle all German troops east of Donetsk. Group Popov was assigned to advance southwards 270 kilometers and capture Mariupol, which would cut off Army Group Don. The corps was given the mission of cooperating with the 57th Guards Rifle Division in advancing southwest from the 6th Army sector to Sloviansk, which was to be captured by 4 February. The corps would then join the 4th Guards Tank Corps in an advance on Kramatorsk. In early February, the Soviet advance was blocked by the resistance of the 7th Panzer Division in Sloviansk. The tank corps of Group Popov were brought in as reinforcements, including the 3rd, and they were able to encircle the city, which fell after holding out for more than a week. Following the advance of the 38th Guards Rifle Division, the corps reached the area northeast of Sloviansk by 4 February. The corps was then ordered to reinforce the 4th Guards Tank Corps, dug in at Kramatorsk and fighting attacks from the 7th Panzer Division. The 3rd Tank Corps joined the 4th Guards at Kramatorsk on 5 February. Both corps numbered a total of 60 tanks at this time. The German troops were reinforced by the 333rd Infantry Division, which claimed to have inflicted heavy losses on both corps, which now defended Kramatorsk with their tanks.