In a large skillet, heat oil over medium heat. Add chicken; cook 8-10 minutes on each side or until no longer pink.
In a small bowl, whisk together water, brown sugar, orange juice, soy sauce, ketchup, vinegar, garlic, pepper flakes and five-spice powder. Pour over chicken. Bring to a boil. Reduce heat; simmer, uncovered, 20-25 minutes or until chicken is tender, turning chicken occasionally and adding more water as needed.