Video: Djokovic-Nadal exchange in thrilling rally in Open final

As we go to an improbably fourth set in this brilliant, epic U.S. Open final, here's a taste of how high the level of play has been between Novak Djokovic and Rafael Nadal:


There's been about 10 other points just like it. Djokovic and Nadal are currently at the three hour, 33 minute mark with Djokovic leading two sets to one. And the rate this is going, they shouldn't expect to be finished any time soon.