In April 1942, Kozin became the commander of the 8th Motor Rifle Division NKVD in the Voronezh area. In June, the division was converted into the 63rd Rifle Division. The division fought in the Battle of Voronezh during the summer. In late November, the division fought in Operation Uranus. The 63rd was part of the 21st Army's main attack and broke through the Romanian-German defenses, advancing southwards. In the area of Raspopinskaya village, the division helped fully encircle two corps of the Romanian Third Army between 21 and 22 November. The 63rd's attacks reportedly split the pocket in half and then simulated a mechanized attack using the division's motor transport battalion. On the evening of 23 November, Romanian 14th Infantry Division commander General Stanescu surrendered the 27,000 troops in the pocket. For his actions, Kozin was awarded the Order of Suvorov 2nd class and the division became the 52nd Guards Rifle Division on 27 November. The division then fought in the Soviet attacks to shrink the Stalingrad Pocket. On 21 January 1943, Kozin was promoted to major general. He was wounded and sent to the hospital. After his recovery, Kozin was sent to study at the Military Academy of the General Staff.