The standard mount escape that is taught to everyone very early in training. I basically do this the same way as other instructors with a few minor changes. My knee to the tailbone to get their hands to the floor and the way that I control the arm are typically different. There are instances when controlling the arm and the shoulder (of the side you're reversing to) is better than the way that I do it, but I find that breaking the arm down can be a problem. If that is a problem for you this variation will help you greatly.
There was some controversy over wether this move was called "upa" or "umpa". The video is title is correct (Upa) but you will clearly hear me say "Umpa" in the video description. I guess that is appropriate considering (upa) in Portuguese is used similarly to the word "oops".