It's interesting that when facing each other over their career in majors, Novak's and Stan's results look like a pair of bookends.
Novak won their first 3 matches - 2 at the US Open and 1 at the AO, two of those lengthy 5 set matches.
Then the two exchanged wins at the Australian Open, both in 5 sets.
Finally, Stan has won the last 3 matches, 2 at the US Open, and 1 at RG, their only clay match in majors, with 0 on grass.
Djokovic won their first match in 2012 at the USO when Stan lost the first 2 sets and retired in the 3rd set (3-1). Stan won their last match (so far) last night when Djokovic lost the first 2 sets and retired in the 3rd set (2-1).
Visually:
[ ND: 2 sets - 0 ret, ND: 3-2, ND: 3-2, | SW: 3-2, ND: 3-2, | SW: 3-1, SW: 3-1, SW: 2 sets - 0 ret.]
As one can see overall, Stan leads Novak 17 sets to 15 sets in slam play.
It's also a bit unusual that Stan, the older player by a little over 2 years, lost his first 3 to Novak, the younger player, early in their slam history, but has beaten the younger player late in their last 3 in their slam history.