Rafa's resolve in the final set was superb. Not satisfied with letting it go to a 5th, had to dig deep to recover in that set and it paid off.
The mental fortitude of both of these players is astonishing though. Djokovic a set and 3-0 down at one point, recovered to take it to 1-1 into the 3rd set. And then Rafa down 3-0 and 5-2 in the 4th, then ends up winning. They find the physical and mental strength out of nowhere.