Preheat oven to 350°F with rack 6" below broiler. Season chicken with rosemary, salt, and pepper.
Wrap each breast with 2 slices of bacon, ending seams underneath.
Sear seam-side down in hot skillet until bacon browns (about 3 min).
Sprinkle 1 tbsp sugar on each breast. Roast until chicken reaches 155°F (15–20 min).
Broil until bacon is crisp and chicken hits 160°F (4–5 min). Rest 5 min before serving.