Prepare the chicken by placing it breast-side down on a cutting board. Using kitchen shears, cut along both sides of the backbone to remove it.
Flip the chicken over and press down firmly on the breastbone to flatten it.
In a small bowl, mix together the olive oil, salt, pepper, garlic powder, onion powder, smoked paprika, dried thyme, lemon zest, and lemon juice to create a marinade.
Rub the marinade all over the chicken, making sure to get under the skin for maximum flavor. Let the chicken marinate for at least 30 minutes at room temperature or up to 2 hours in the refrigerator.
Preheat your grill to medium-high heat (about 375°F to 400°F).
Place the chicken skin-side down on the grill. Cook for about 15-20 minutes, then flip and cook for an additional 15-20 minutes, or until the internal temperature reaches 165°F in the thickest part of the breast.
Remove the chicken from the grill and let it rest for 10 minutes before carving.