Stir red wine, peppercorns, sugar, and salt together. Pour over steak in a baking dish or large plastic resealable bag and allow to marinate for 3 to 24 hours in refrigerator.
Heat a large skillet over high heat. Remove steaks from marinade and place in hot skillet. Cook each side until nicely browned, 2 to 3 minutes per side.
Pour the marinade into the skillet and simmer until cooked to your preference, about an additional 5 minutes. Remove steaks from pan and allow to rest for 5 minutes. Continue to simmer the red wine sauce to reduce by half.