Wrap water chestnuts in bacon and secure with a toothpick. Layer on a broiler pan. Bake at 400 for 15 minutes until crispy and most of the grease drips off. Remove chestnuts from broiler pan, place on paper towel to drain some more and then put chestnuts in a oven proof casserole dish.
Mix ketchup, brown sugar, Worcestershire sauce, Teriyaki sauce and garlic powder in small bowl.
Pour sauce over water chestnuts in casserole dish.