Djokovic had been threatening a sporting miracle when the final continued in showers and sunshine on Monday, with the top seed leading 2-1 with a service break in the fourth set.
He had trailed by two sets and 2-0 on Sunday before winning eight straight games in an extraordinary turnaround as Nadal moaned to tournament referee Stefan Fransson about playing in persistent drizzle for almost three hours before the match was abandoned for the night.
The prospect of Djokovic being only the second player in 76 matches to conquer Nadal in a best-of-five-sets claycourt encounter could not be ruled out.
In an incredible 27-match grand slam winning streak, Djokovic saved two match points in last year's US Open semi-finals against Roger Federer, recovered from a service break down in the fifth set to deny Nadal in a near-six-hour epic Australian Open decider and fought off four more match points against Jo-Wilfried Tsonga in the quarter-finals in Paris last week.
The Serb also trailed Andreas Seppi two sets to love in the fourth round.
But a comeback from two sets and a break down against the greatest claycourter in history proved beyond even this modern-day tennis Houdini.
Nadal broke Djokovic in the first game upon the resumption on Monday to level at 2-2 in the fourth set.
He then took the match on a Djokovic double-fault and burst into tears after three hours and 49 tension-filled minutes - three hours on Sunday and 49 minutes on Monday.
Djokovic had been striving to become the first man since Laver in 1969 to complete a grand slam sweep - and only third ever including Don Budge in 1938 - after claiming the Wimbledon, US Open and Australian Open trophies in six supreme months.
Conquering Nadal on red dirt has proven nigh impossible since he captured his maiden French Open on debut as an 18-year-old in 2005.
He's lost just once in 53 matches at his Paris fortress - to Swede Robin Soderling in the fourth round in 2009 when Nadal's knees failed him and forced him to abandon his subsequent Wimbledon title defence two weeks later.
In stopping Djokovic, the second-ranked Nadal also avoided becoming the first player ever to lose four successive grand slam singles finals.
- AAP