After the beginning of the German invasion of the Soviet Union,
Operation Barbarossa, on 22 June 1941, Nikitin led the corps in the
Battle of Białystok–Minsk as part of the
Western Front. The corps fought in the area of
Pukhovichy, on the
Berezina River, and north of
Bobruisk. After the corps lost all its tanks in an unsuccessful counterattack, it retreated to Mogilev, whose garrison Nikitin commanded during the
Siege of Mogilev until being wounded and evacuated on 16 July. After the destruction of the corps, he was appointed deputy commander of the
49th Army. In this position, Nikitin participated in the Mozhaysk–Maloyaroslavets Defensive Operation, the Tula and Kaluga Offensives during the
Battle of Moscow, and the
Rzhev–Vyazma Offensive. He served as inspector of the cavalry of the
Bryansk Front from March 1942. Red Army cavalry inspector General
Oka Gorodovikov evaluated Nikitin's performance in this position as that of a "disciplined and demanding commander able to instill iron military discipline", before Nikitin went to Moscow on 1 August. Despite Gorodovikov's evaluation, Nikitin was not given a combat command but instead was sent to the
Ural Military District in October to form the 3rd Training Rifle Brigade in Tyumen, which he was appointed commander of. Placed at the disposal of the Cadre Department of the Red Army in May 1943, Nikitin became commander of the 5th Reserve Cavalry Brigade of the
North Caucasus Military District in October of that year. He was evaluated as "failing to establish the right relationship with the [brigade] officers," which was "reflected in the combat training of the brigade," and as a result was relieved in June 1944, being placed at the disposal of the Commander-in-Chief of the Red Army Cavalry. Nikitin was sent back to the front in August as deputy commander of the
32nd Cavalry Division of the
3rd Guards Cavalry Corps of the
2nd Belorussian Front, participating in the
East Prussian Offensive. Another negative evaluation, that he "showed his low training by allowing regimental commanders to withdraw units from captured positions" during the offensive, resulted in his relief in February 1945. Nikitin became acting inspector of cavalry of the
2nd Ukrainian Front in April, ending the war in that position. == Postwar ==