Preheat oven to 350°F. Mix sage, seasoned salt and black pepper in small bowl.
Place turkey breast on rack in foil-lined roasting pan. Spread seasoning mixture over entire surface and under skin of turkey breast. Cover loosely with foil.
Roast 1 hour. Remove foil. Add water to pan. Roast 1 to 1 1/2 hours longer or until internal temperature reaches 165°F, basting occasionally with pan juices. Remove turkey breast from oven. Cover loosely with foil. Let stand 15 minutes. Transfer to platter or carving board and slice.