Nadal is looking to become the first player to win 12 or more titles at the same Grand Slam, surpassing Margaret Court's capture of 11 Australian Opens.
With Thiem leading 4-1, the rain returned, sending players to the locker room for a full hour while groundskeepers scurried to cover the clay court.
The finals match between Nadal and Thiem is set to begin at 9 a.m. Nadal will have had a over 36 hours of rest in advance of his title defense, whereas it will be the fourth straight day Thiem has had to play tennis. "I said a year ago that I hope to get another chance in a Grand Slam final and hope to do better then, so tomorrow there is the chance".
Rafael Nadal and Roger Federer had completed their semi-final in similarly tricky conditions.
Djokovic and Thiem have already played for three days in succession.
World number one Djokovic had been targeting a Grand Slam sweep for the second time in his career coming into the tournament. But a sensational forehand pass by Thiem gave him a fourth set point which he converted when his dipping backhand forced a volley error.
"One of the worst conditions I have ever been part of", Djokovic said about Friday.
However, the Austrian won their most recent meeting on clay in the semi-finals in Barcelona in April in straight sets.
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Juventus sporting director Fabio Paratici has contacted Old Trafford chiefs to discover the World Cup winner's availability. The former Argentina forward also had a dig at the club's record signing: "With United I liked Ander Herrera ".
Djokovic was a point from losing when Thiem served at 5-3, 40-15.
Before we talk about today, play was suspended yesterday. "You can ask (the tournament supervisors)".
He served out and then found a break that made it look as if the momentum of the match would completely swing a double fault played a part of a awful service game from the Serbian and Thiem broke straight back but he struggled with nerves at crucial moments.
Under pressure in the 12th game Djokovic was given a time violation and then saved three set points.
"I didn't know that an umbrella is not a flying object, which flew in in the first game of the match, but that's their decision".
"If someone reaches the final here it is always against Rafa", Thiem said about the 11-time champion.
Thiem's last few games have been incredible which includes him eliminating World. The Austrian, who had been helped by some fortuitous net cords, broke for 3-1 in the decider but then had to go off for rain with the score poised at 4-1 and deuce.
In gusty winds Thiem's powerful groundstrokes helped him dominate the first set and Djokovic was in trouble early in the second when he fended off a break point.
And on a break point, he snatched at his backhand and sent it into the net.