Mix together brown sugar, amber ale and teriyaki sauce in a ziploc bag. Add steak to bag, coating well. Refrigerate overnight.
Light charcoal grill and let coals ash over before cooking.
Just before placing steaks on grill, remove from marinade and rub both sides with a mixture of pepper, garlic powder, seasoning salt and cayenne.
Cook on grill to desired doneness, flipping meat as needed.
Heat leftover marinade on stove to boiling and continue to simmer while steaks cook. In last few minutes of cooking, baste tops of steak with marinade.