Use the following trick when on the ground with your opponent and they try to make a transition. Tap the Right Analog-stick Left or Right to get a reversal. If unsuccessful, you should still block the transition.
When on top of your opponent on the ground, execute a punch or knee, then tap the Right Analog-stick Left or Right, and repeat. This will block them from transitioning to a better position and helps you advance to a better position or keep a good position.