It will be their 31st career meeting, with Nadal leading 16-14 but having lost the last 7 (final) matches the two have contested.
If Djokovic wins this match he will basically have demonstrated that he can beat Nadal anywhere, anytime and may never lose to him again. Nadal is playing well, in his first clay tournament of the season, on the surface where he is considered the best player of all time. Nadal has not dropped a set all week long. Djokovic, on the other hand, is not playing that well, although he managed to dispatch Robin Haase in straight sets just hours after he received the distressing news that his grandfather had passed away on Thursday. Instead of withdrawing from the tournament, Djokovic rallied to beat Tomas Berdych in a 3-set semifinal.
I think this will be an excellent match, but I think one has to give the edge to Nadal this time. Djokovic does have his number, but I find it impossible to believe that anyone could beat Nadal 8 times in a row, especially in 8 consecutive finals! Djokovic will have a mental escape hatch in the death of his father. I don't think this potential loss will prevent Djokovic from beating Nadal on clay in other tournaments this season.
MadProfessah's prediction: Nadal in 3 sets.