The Greek star was playing the big points much better than the Serb, who made some uncharacteristic errors in a difficult first set.
But any hopes of a second set fightback were replaced with more concern as Djokovic was broken in the third game of the second set to put him in big trouble as the rain came down in Italy.
Immediately after losing his serve and going 2-1 down in the second set, play was suspended due to the worsening conditions on court, with Djokovic’s stony expression hiding what was likely relief at some respite and the chance to reset before play resumes.
“It was very clear what happened,” he told Amazon Prime Video after his win.
“Some lines are higher than the rest of the court so when you touch the line it’s dangerous. That’s it.”
But, despite his injury scare, Nadal declared himself satisfied with his performance as he eased into the final four of the tournament.
“I’m happy. Semi-finals here in Rome one more time, confidence for myself and another victory against a great player so very pleased.
“I think I played more solid than in Madrid. At the same time conditions are different.
“In Madrid, he was able to create a lot of damage with his serve and then with the first shot here, the situation is a little bit different, a little bit more normal conditions on the clay.
“I was able to control the game a little bit more than in Madrid where the ball was flying a lot and it was difficult to be under control. At the same time, the main thing is that I played well.”
This post originally appeared on Daily Express :: Sport Feed