Place chicken breasts on flat work surface and sprinkle with 1/2 teaspoon salt and 1/2 teaspoon pepper. On the top-side of 1 breast, place 1 slice of pancetta over the lower portion of the breast, wrapping it snuggly to adhere. Place a safe leaf on the center of the breast and wrap the upper portion with a section slice of pancetta. Turn breast over and wrap a third slice over the back of the breast. Repeat with remaining chicken, transferring pieces to plate as you go. (Chicken can be made in advance up to this point. Wrap tightly in plastic wrap and refrigerate until needed.)
Preheat oven to 450°F. Position one oven rack in lower third of oven and other rack in upper third. Slice potatoes lengthwise into 1/4 inch to 1/2 inch slices; then cut slices into 1/4 inch thick fries. Toss potatoes, lemon halves, 4 tablespoons olive oil, 10 sage leaves, and remaining salt and pepper in a large bowl until well-coated. Arrange potatoes in single layer on large baking sheet; place on lower rack of oven. Bake 15 minutes. Gently stir potatoes, return to oven and bake until browned on all sides, about 30 minutes more.
While potatoes are cooking, heat large skillet over high heat until very hot. Drizzle pancetta-wrapped chicken with oil and place in pan, sage leaf side down. Cook chicken over low heat until pancetta is brown, about 5 minutes. Turn chicken over; transfer pan to upper rack of oven and roast for 15 minutes, until cooked through.
Remove chicken from pan, transfer to plate and set aside. Add wine to pan and stir to deglaze, over high heat. Cook until wine is almost evaporated. Add chicken stock. Continue to cook until liquid is reduced by half.
Transfer chicken and potatoes to large serving platter. Squeeze juice remaining in lemon halves over potatoes. Serve with pan juices on the side.