Mix soy sauce, lemon juice and oil together in a large resealable plastic bag. Rub garlic power into meat, place in bag, and seal. Marinate in the refrigerator for at least 4 hours; turn bag after 2 hours.
Preheat grill for medium heat.
Oil grate lightly, and place meat on grill. Discard marinade. Cook steak for 5 to 7 minutes per side, or to desired doneness.