Zuzic was credited with 13 victories. Oberfeldwebel Wintergest had a remarkable feat: On 12 August 1941 he had attacked alone a formation of seven SB-3 bombers between Zebrikovo and Odessa, and he shot down all of them. At first this was not beleived by his superiors, so his commander Hauptmann Anton Mader took off to check it, and he found all seven bombers lying in a row. This was Wintergest's 8th to 14th victories. His last, and 20th, victory was achieved over a MiG-3 near Preobrashenko (while escorting He 111s attacking this target) at 17:20 hrs on 23 September 1941.
On 24 September 1941, they were literally linked together over Russian-held territory north of Perekop: The Bf 109 E-7 (W.Nr. 3632, "white 13 + - ") piloted by Oberfeldwebel Eugen Wintergest and the Bf 109 E-4 (W.Nr. 1459) piloted by Leutnant Herwig Zuzic collided in mid-air and had to force-land behind the Russian lines. 10 to 14 days later, Russian aircraft dropped leaflets on the base of II./JG 77. On these leaflets were the picture of Leutnant Zuzic and an appeal to his friends to fly their planes over to the Russian side and desert.
Some months later, both Zuzic and Wintergest were parachuted into Rumania by the Russians to act as spies. Both turned themselves over to German authorities and said that they had fooled the Russians that they had gone over to the Russian side. They were put back in service as fighter pilots, but not on the Eastern Front. In March 1943, Zuzic (promoted to Oberleutnant) was made leader of the new 8./JG 1 in the Home Defense, and Wintergest (promoted to Leutnant) was made leader of 9./JG 1.
On 27 July 1943, Oberleutnant Zuzic shot down a B-17 "Flying Fortress" - his 14th and last victory. On 19 August 1943, Zuzic collided with another Bf 109 G-6. This time, he had run out of luck and was killed. His death hit his friend Wintergest very hard. Wintergest told his friends: "We've lived through so much together, now I think we'll die together".
On 4 September 1943, Wintergest's 9./JG 1 got involved in a very difficult combat with "Spitfires" over Dunkirk. Against only one Spitfire shot down, six Bf 109s were lost - including "yellow 1", piloted by the Staffelkapitän Leutnant Eugen Wintergest. Wintergest tried to get out of his spinning Messerschmitt, but as he finally managed to get out, the altitude was too low so the parachute didn't open. Eugen Wintergest fell to a certain death.
