Pics aren't bad.
What kind of camera are you using?
A setting like this is where a full frame/35mm camera is beneficial. You will want an ISO of probably 1000 (Possibly a little more), and and a shutter duration of 1/500 to 1/1000 of a second (or higher) if you can get away with it. The shutter duration you use will depend on how close you are to the action (Closer requires a shorter shutter duration).
Fast prime lenses with low f stops f1.4-2.0 will help a lot. If you use a good zoom, its lowest f stop will be f2.8 which is also good and should also work well since the UFC events always have very good lighting.
Lastly, I would recommend that you correct your white balance. Your third photo appears to have the most accurate white balance, all of the others are too yellow.
Here are a couple of my most recent MMA pics: