How do you beat team galactic at mt cornet in Pokemon Diamond?

To beat them, gothrought the Maze cave, Mt. Coronet. Get to the top in Spear Pillar and You see Galactic Admins. Walk to them. You start to speak to Mars, when she gets mad at you. Jupiter wants to watch you lose, so she teams up with her. Rival burst to the center and joins you for a 2 on 2. Then win. You see Cyrus using the Red Chain. Dialga comes. The three pixies come to help you. My memory's a bit foggy here, but anyway, Catch or Beat Dialga. You Beat Cyrus' Master Plan!