Preheat your oven to 425°F (220°C).
In a large bowl, combine the olive oil, garlic powder, onion powder, smoked paprika, dried thyme, salt, and black pepper. Mix well to form a marinade.
Add the chicken thighs to the bowl and toss to coat them evenly with the marinade.
Place the halved baby potatoes on a large sheet pan. Drizzle with a little olive oil and sprinkle with salt and pepper. Toss to coat.
Arrange the marinated chicken thighs on the sheet pan with the potatoes. Place lemon slices on top of the chicken.
Bake in the preheated oven for 35-40 minutes, or until the chicken is cooked through and reaches an internal temperature of 165°F (74°C) and the potatoes are tender.
Optional: For extra crispiness, broil for an additional 2-3 minutes at the end of cooking.
Remove from the oven and let rest for 5 minutes before serving. Garnish with fresh parsley.