Following his return to the front, JG 77 was assigned to the newly created Army Group B in support of "Fall Blau" (Case Blue), the "Wehrmacht"'s 1942 strategic summer offensive in southern Russia. On 5 July 1942, II./JG 77 was based at Kastornoje, approximately west of Voronezh, where it fought in the Battle of Voronezh. Setz briefly commanded II./JG 77 in July for "Gruppenkommandeur" (group commander) Anton Mader. He claimed two MiG-3s on 23 July 1942. On the next day, 24 July, he reached his 100th aerial victory. He was the 13th Luftwaffe pilot to achieve the century mark. This achievement earned him German Cross in Gold () which was awarded to him on 21 August 1942. On 16 September, Setz, for the second time, became an "ace-in-a-day" after he claimed the destruction of three LaGG-3 fighter aircraft and two Ilyushin Il-2 ground-attack aircraft, taking his total to 133 aerial victories. Setz's 4. "Staffel" was then reequipped with the Bf 109 G-2 and transferred to an airfield at Stary Oskol on 23 September 1942. On 2 October, 4. And 6. "Staffel" flew a fighter escort mission for a flight of Heinkel He 111 bombers attacking Soviet positions north of Voronezh. On this mission, Setz claimed two LaGG-3, his last victories on the Eastern Front. This took his total to 135 aerial victories. Setz was promoted to "Hauptmann" on 1 November 1942. On 7 November 1942, II. "Gruppe" received orders from "Generalmajor" Alfred Bülowius, the commander of the 1. "Flieger-Division" (1st Air Division), to relocate to the North African theater of operations.