During the fighting in 1943, JG 54 took part in the spring battles over the Crimea Peninsula, Vyazma-Bryansk, Vitebsk, Kharkov, Orsha and Orel regions. During the Battle of Kursk, Kittel's unit escorted Junkers Ju 87 "Stukas" of a dive bomber wing commanded by Hans-Ulrich Rudel. On 14 September 1943, Kittel claimed his 100th aerial victory, a Yakovlev Yak-9 fighter. The 53rd "Luftwaffe" pilot to achieve the century mark, he received the Knight's Cross of the Iron Cross () on 29 October 1943. On 1 November 1943, Kittel was promoted to the rank of "Leutnant" (second lieutenant).