After the 380th departed for the 1st Shock Army of the Northwestern Front, fighting southwest of Demyansk on 31 December, Smirnov transferred to command the 6th Guards Airborne Division in March 1943, which he led for the rest of the war. He led the 6th Guards Airborne in the failed Staraya Russa Offensive, after which it was withdrawn to the Reserve of the Supreme High Command (RVGK) in April. With the 5th Guards Army, it fought in the Battle of Prokhorovka during the Battle of Kursk in early July, then in the Belgorod-Kharkov Offensive. For his "constant and skillful leadership" of the division in the initial stages of the latter, Smirnov received the Order of the Red Banner on 5 September. From early September Smirnov led it in the Battle of the Dnieper. He was promoted to major general on 16 October. During the remainder of the war, Smirnov led the division in the Kirovograd Offensive, the Korsun–Shevchenkovsky Offensive, the Uman–Botoșani Offensive, the Second Jassy–Kishinev Offensive, the Budapest Offensive, the Bratislava–Brno Offensive, and the Prague Offensive. For his "exemplary fulfillment of command orders" and "courage" in the Second Jassy–Kishinev Offensive of late August 1944, Smirnov was awarded the Order of Suvorov, 2nd class, on 13 September of that year.