Go over the steak with a tenderizer, or pierce with a fork many times.
Whisk the vinegar, olive oil, liquid smoke, salt, and black pepper in a bowl. Transfer to zip lock bag and add the steak.
Coat the steak completely and marinate in the refrigerator. Leave at least 30 minutes before cooking.
Preheat the George Foreman grill for 5 minutes, with the lid, closed, on the highest setting.
Slice the garlic clove into thin slivers. With a sharp knife, make several 6-8 slices on each side of the steak.
Place the garlic slivers into the holes.
Place the steak on the grill and close the lid. After 4 minutes, check and rotate 1/4 turn.
Once cooked, allow it to rest for 3-4 minutes before serving.