Preheat the oven to 400°F (200°C).
Pat the chicken breasts dry with paper towels.
In a small bowl, mix together the garlic powder, smoked paprika, dried thyme, dried oregano, salt, and black pepper.
Rub the olive oil evenly over both sides of each chicken breast.
Sprinkle the seasoning mixture evenly over both sides of the chicken breasts, pressing gently to adhere.
Place the seasoned chicken breasts in a single layer in a baking dish.
Arrange lemon slices on top of and around the chicken breasts.
Bake in the preheated oven for 22 to 25 minutes, or until the chicken reaches an internal temperature of 165°F (74°C) and the juices run clear.
Remove the chicken from the oven and let it rest for 5 minutes before serving.