On 17 April 1943, Rudorffer was appointed "Gruppenkommandeur" (group commander) of II. "Gruppe" of JG 2. He replaced "Hauptmann" Adolf Dickfeld in this capacity who had been transferred to II. "Gruppe" of "Jagdgeschwader" 11 (JG 11—11th Fighter Wing). A little over two months later, on 30 June, he was transferred again, taking command of IV. "Gruppe" of "Jagdgeschwader" 54 (JG 54—54th Fighter Wing) on the Eastern Front. Command of II. "Gruppe" of JG 2 was handed over to "Hauptmann" Kurt Bühligen. He claimed his first victory in that theater on 7 August. Due to the experience gained in combat with the RAF he achieved considerable success. During his first sortie on 24 August 1943, 5 Soviet aircraft were downed in 4 minutes.