Djokovic downs Murray in thriller
World number one Nadal reached his sixth consecutive final this year after brushing aside Frenchman Richard Gasquet 7-5 6-1 but second seed Djokovic was forced to scrap for his victory.
The Serb won a late-night third-set tie-break to beat his British opponent 6-1 3-6 7-6 in an exhilarating three-hour encounter to stretch his unbeaten run this year to 36 matches.
"It was a fantastic match and whoever saw it knows how close it was," said second seed Djokovic, who has won six straight tournaments this year including a first victory on clay over Spaniard Nadal at the Madrid Open last week.
"He (Murray) played really well. I had to earn my points as he wasn't making a lot of errors. It took a lot out of both of us and unfortunately someone had to lose."
On finishing the match after 23:00 local time, the Serbian said he would try to recover to be fully fit for Sunday's final which is scheduled at 16:15 CET.
"I made the mistake of playing 40 games in the past four months -- that's what went wrong in the second set," he said. "I've played more matches than any player, so it's normal that you get exhausted. I will do my best to recover for tomorrow."
Djokovic broke Murray's serve in the second game and then twice more as the Scot struggled to live with the Serb's power and precision in the first set.
But Murray, who had won three of their previous four confrontations, found the slower pace of the second set much more to his liking, prospering in the long backhand rally exchanges and breaking in the fifth game to square the match.
In a thrilling deciding set, Djokovic broke Murray's serve in the fifth game but the gutsy Scot refused to give up on a single point and broke back for 3-3 with a blistering backhand followed by a forehand as the momentum swung back his way.
Four more breaks of serve followed at an increasingly noisy Foro Italico as Murray broke the serve of an exhausted-looking Djokovic for a third time in the set for 5-4 but, helped by two double faults, the Serb summoned the energy to break back again in a game lasting more than eight minutes.
Djokovic was always ahead in the tie-break, producing a drop shot and then a lob to reach 6-2 before sealing the match with another drop shot as he let out a loud victory scream to underline how close he had come to losing his unbeaten run.
"I probably should have won," Murray, who celebrates his 24th birthday on Sunday, said. "I'm one of the best closers on the circuit. I think it's the first time I haven't finished a match on serve and I hope it's the last."
"The supposed crisis I was in is over," he said. "I was in a bad place mentally but my tennis will never go away. I feel I can compete with those guys at the top. I feel I'm moving well on clay and I definitely think I can win the French."