When my son was 2 years old he also began to fight me during diaper changes and would run off as well when it was time to change his diaper.
It was just that he didn't like to be interrupted during his busy time playing and lay down to get his diaper changed and he seemed to like staying in and wearing his wet or poop filled diaper.
If I would have let him he would have stayed in the wet and dirty diaper all day but that's not possible because he would get a rash and it would be neglect.
What you should do is warn your 2 year old in advance of the diaper change and say that in a few minutes you need to stop playing or doing this and get your diaper changed.
He still may fight you but giving him warning will sometimes stop the diaper change battles.
You might have to hold him down and have somebody else help hold him down while you change his diaper because some children just eventually start hating having their clothes ripped off and having their diaper changed.
I sometimes had to hold my 2 year old down and he would scream and fight the diaper change so I tried to potty train him and he still wouldn't potty train so I told him that he either had to wear the diapers and deal with diaper changes or use the potty.
He eventually started potty training after age 3 and after age 2 he started stopping with the diaper change fights.
The diaper change battles will eventually stop and you'll likely just have to put up with it until he's potty trained or begin potty training him.
Or give him a toy or something such as a tablet etc to watch cartoons or something on while you change his diaper because sometimes by distracting the toddler will stop the diaper change battles because he will be distracted.