Adventures of Captain America (1991) #4
"Angels of Death/Angels of Hope!" Written by Fabian Nicieza. Art and cover by Kevin Maguire.
Thus begins the epic conflict between Captain America and the man who is destined to become his greatest foe, the Red Skull! The year is 1940, and Cap is on his very first adventure! He's been captured by the Nazis and taken prisoner in a concentration camp. Cap has been brought here (along with his young ally, Bucky) for one purpose" to battle the Red Skull to the death in a Roman-style colosseum! The Skull thinks this match will be a great propaganda tool for the Third Reich. He wants to deal a blow to the morale of the American people, as the living symbol of the American dream is to be humiliated before a huge audience. For Cap, it's a chance to prove he has what it takes to be the super soldier, and to strike a major blow for freedom. The die is cast. There can be no turning back now. This will be the ultimate battle between the greatest warriors of two nations. For both Cap and the Red Skull, this may well be the most important fight of their lives. The fate of the free world is at stake. If Cap loses, we all lose!