In a skillet, cook bacon over medium heat until crisp. Using a slotted spoon, remove to paper towels to drain. Saute onion in drippings until tender; drain. Stir in the brown sugar, ketchup, Worcestershire sauce and mustard until blended. Stir in pork and beans; heat through.
Transfer to a greased 3-cup baking dish. Bake, uncovered, at 350° for 40-45 minutes or until bubbly and mixture reaches desired thickness.