If I'm on a horse that wants to run I might let it and then push it past where it wants to run untill stopping is the horses idea.
You also shouldn't ride expecting a problem. You can think about the problems and plan ahead but if you expect your horse to misbehave then you will not be disappointed.
As for Kevin's suggestion, I'm fine with it except that stopping has to be my idea, not his. In this case I would keep him running and when he wanted to stop - I'd keep him running a little more then bring him up fast.
Depending on the horse, running him may only make him hyper and he becomes a handful for the rest of the ride. That is a whole other issue and not the point of this thread.