As soon as the battle begins, the dragon will lower its head for you. Have the Dragon Sword at level 3 and use the X(2), Y(3) combo on it. Then, run to one of the raise-able platforms and keep running forward towards the dragon. You will not fall off unless you jump. If the platform is raised, keep on running forward; do not get on the upper platform. When it shoots a fire ball, roll forward. When it flaps its wings, roll forward. You will receive no damage. Then, just attack when it lowers it head.