He received the Knight's Cross of the Iron Cross () on 1 July 1942. The presentation was made by Major Hubertus von Bonin. Gratz was one of four JG 52 pilots presented with the Knight's Cross that day. The other three pilots to receive the distinction that day were Feldwebel Alfred Grislawski, Feldwebel Karl Steffen and Oberleutnant Siegfried Simsch. By late 1942 29 more victories had been claimed.
