1 beef brisket (4-5 lb. size)
1/2 teaspoon celery salt
1/4 teaspoon garlic powder
1/8 teaspoon onion powder
2 teaspoons liquid smoke
1/3 cup Worcestershire sauce
3/4 cup barbecue sauce
Sprinkle beef with celery salt, garlic powder, and onion powder. Place in a shallow dish. Pour liquid smoke and Worcestershire sauce over meat. Cover with aluminum foil, and refrigerate overnight, turning once.
Cover and bake at 300 degrees for 4 hours or until tender. (Time varies depending on oven and meat.) Pour off liquid, reserving 1/2 cup.
Combine barbecue sauce and 1/2 cup liquid, stirring well. Pour sauce over beef. Bake uncovered an additional 30 minutes.
To serve, slice across grain into thin slices.