Paul Hitchens has put together a fantastic reconstruction of a deleted scene from the Transformers: The Movie which he has shared on his The Spacebridge page over on Facebook.  The video, which is on YouTube, shows what happens between Optimus Prime ploughing through the Decepticons and then coming face-to-face with Megatron.  Here is Paul to give a better explanation

"Here is a video I made of one of the deleted scenes from the 1986 Transformers movie. It's made using a set of production used storyboards I own. I have included a section of the film either side so you can see where it would have fit in. I believe this scene was animated as it exists in very late production notes & music was written to accompany it. It was cut as Nelson Shin felt it ruined the flow of Primes attack leading up to his battle with Megatron. Ultra Magnus, Tracks, Sideswipe & Red Alert were picked to attack Devastator as they all have rocket launchers. It also explains what Megatron was looking at when Prime found him. Hope you like"