Fighting ability isn't everything. For spiderman can beat Cap. Spiderman's fighting ability is a 4 and cap's a 7.
So it boils down to other abilities. DD's sense powers definitely outweighs batman's fighting ability. Many comics are written with PIS. And people used them as proof. Again, DD can sense the weakness in bat's suit and thus form attacks based off that info. DD also has a unique fighting form. Something batman has not saw before. If DD can intercept bullets without it being PIS then I don't see batman laying a hand on DD without it being PIS. This will definitely be a great fight though. I would probably pay everything I own just to see it. I believe DD takes this due to his ability to sense bat's attacks and sense a weakness through bat's suit. Intercepting bullets got to count for something. Right?