Mix together the pineapple juice from the can of pineapple rings, soy sauce, brown sugar, and garlic powder together in a zipper bag until all the brown sugar is dissolved. Add the pork chops and zip closed. Refrigerate overnight.

Preheat grill to medium-high heat. Remove chops from bag and place on grill. Brush pork chops with marinade mixture while they are cooking. 

Grill until pork chops are browned and no longer pink inside. Usually about 6-8 minutes per side, depending on thickness of chops.

While pork chops are cooking, place pineapple rings on grill and cook until they have grill marks on both sides. Serve pork chops with grilled pineapple on top.