Djok the only player to have won 3 sets in a row against Nadal in a slam final - AO19. That was the only time it happened.
Fed lost 3 sets in a row at RG06 and RG08... they remained the only two times it happened to him in a slam final.
Djok had 3 sets in a row in slam finals the following occasions:
US07 f v Federer
WIM13 f v Murray
RG14 f v Nadal
RG15 v Wawrinka
US16 v Wawrinka
RG20 v Nadal
US21 v Medvedev
seven times! idemo...