Nikitin joined the Red Army in May 1918 during the Russian Civil War and became commander of a "sotnya" of the 5th Soviet Cossack Regiment on the Tsaritsyn Front, then became a squadron commander in the 4th Peasant Cavalry Regiment of the Brigade under the command of Bulatnikov from October of that year. He became assistant commander of the 22nd Voronezh Cavalry Regiment of the Separate Cavalry Division (the 4th Cavalry Division from March) of the 10th Army in January 1919. The division became part of Semyon Budyonny's Cavalry Corps in June 1919, which was expanded into the 1st Cavalry Army in November of that year. With the division, Nikitin fought on the Southern Front in the Battle of Tsaritsyn and the territory of the Don Host Oblast in the Voronezh–Kastornoye Operation, the Kharkov Operation, the Donbass Operation, the Rostov–Novocherkassk Operation, the North Caucasus Operation, and the Battle of Yegorlykskaya.