How big is the paddock? I would put him in a smaller space so if he avoids being caught you can run him around you until he decides it's much easier on him to be caught without fuss. If you like him being in a larger area, you can do what i did. I put a round pen in one corner of my larger paddock so I could herd my daughter's cagey little pony into it. I made a point of going up to her in the field. She would promptly run from me, so I would herd her in, then shut the gate and run her little butt in circles every time I went out there. When she stopped I went up to her, gave her a scratch and a goody, and left her alone, leaving the gate open behind me so she could get back out. After a few weeks of that she would get into the roundpen, realize she was as good as caught, and let me approach. A few weeks of that and the roundpen was no longer necessary.
Definately try to nip the running in the bud as it is a frustrating habit, as I am sure you already know :)