Preheat oven to 250 F. In a small bowl, combine brown sugar, salt, paprika, pepper, garlic powder, onion powder, and chili powder.
Rub dry rub seasoning over brisket and place into a large baking dish. Cover with foil and bake for 4 hours. Uncover and pour barbecue sauce over the top. Bake uncovered for another 40-60 minutes.