Nadal, a four-time Madrid champion, improved to 14-0 on clay this season and reached the final of the ATP World Tour Masters 1000 event for the seventh time in nine years.
"What's important to me is to make it to another final," said the fourth-seeded Nadal, who beat No. 2 seed Djokovic for the first time since the 2014 French Open final. "As time goes by, what is important is the titles, not the opponents that you have beaten. It's just the titles that you have won.
"It's true that some matches are more important than others. But I'm just here to try to make it the best possible way, to play my best tennis, and of course to beat an opponent such as Novak, it gives you a lot of confidence. It shows you you're working in the right way."
Nadal, who moved to No. 1 in the Emirates ATP Race To London with a quarterfinal victory over David Goffin on Friday, fired 20 winners, including seven with his backhand.
With a victory on Sunday, he would tie Djokovic atop the Masters 1000 titles leaderboard with his 30th crown.
"Rafa was obviously a better player today," Djokovic said. "He deserved to win. He was controlling the match from beginning to the end. All in all, I did try my best. It wasn't a very high quality of tennis from my side. I made a lot of unforced errors, especially in the first set.
"Just his quality was very high. He managed to do whatever he wanted, especially in the first set. I was getting a lot of balls back. He was serving well. He was using his court positioning well. Today was warmer than last three, four days, so conditions were quite different. The ball was bouncing very high. He managed to be better in these kind of conditions."
Djokovic had 13 unforced errors in the first set and never really got untracked.