In many years of sales I've learned it's best to travel the high road. There have been numerous instances of co-workers and bosses not travelling that road. Generally they get caught. When it would get too bad, I've gone up a step (generally never do) if they've impacted me directly. With a no-nonsense reputation, I was generally listened to as didn't make a habit of being a "tattle-tale." It had to be really bad for me to say something.
Usually liars trip themselves up as it's tough to be consistent in those lies. The key is documentation as the others have said and developing an aura of someone who shouldn't be crossed.