In a bowl, combine Piri Piri sauce, minced garlic, lemon juice, olive oil, smoked paprika, dried oregano, brown sugar, salt, and black pepper. Mix well to create the marinade.
Pat the chicken leg quarters dry with paper towels.
Place the chicken in a large resealable bag or a shallow dish.
Pour the Piri Piri marinade over the chicken, ensuring it is well-coated. Seal the bag or cover the dish and refrigerate for at least 4 hours or overnight for maximum flavor.
Preheat the grill to medium-high heat.
Remove the chicken from the marinade, allowing any excess to drip off.
Grill the chicken leg quarters for approximately 20-25 minutes, turning occasionally, until the skin is crispy and the internal temperature reaches 1650F (740C).
Baste the chicken with any remaining marinade during grilling for added flavor.
Remove the Piri Piri Chicken from the grill and let it rest for a few minutes before serving.
