Line a large roasting pan with heavy foil, letting ends of foil hang over edges of pan. Place brisket in pan, sprinkle the sugar, soup mix and garlic powder over the brisket. Drizzle ketchup over all. Fold ends of foil over beef, sealing securely and leaving air space. Bake in 325 degree oven for 3 to 3 1/2 hours or until beef is tender. Transfer beef to platter and slice. Skim fat from sauce. Serve sauce immediately with beef.
To make ahead and reheat; after cooking, cool and slice beef. Skim fat from sauce. Store brisket and sauce in separate storage containers. Chill meat and sauce up to 2 days.
To serve, transfer meat to an 8x8 inch baking dish. Pour sauce over all. Bake, covered in 325 degree oven for 25-30 minutes.
