Djokovic dropped a set for the first time this week against the Greek world number five.
But the Serbian still extended his winning streak against Tsitsipas to eight matches with a 6-2 3-6 7-6 (4) victory.
"It's very sweet, obviously, when you win matches like this against one of the best players in the world," Djokovic said after the victory. "I thought I started the match very well, again, great hitting like yesterday in the quarters. I had chances early on in the second, I didn't break his serve. The momentum shifted, the crowd got into it. I think he elevated his level of tennis.
"Deservedly so, we went into - both of us - into an even battle all the way until the last point, until the last shot. Some incredible points towards the end. I'm just really glad to overcome this challenge."
Djokovic will face unseeded Danish teenager Holger Rune, who was a surprisingly comfortable 6-4 6-2 winner against in-form Canadian eighth seed Felix Auger-Aliassime, in Sunday's final.
Alcaraz out for the season
Meanwhile, world number one Carlos Alcaraz has announced he will miss the ATP Finals and the Davis Cup through injury.
The US Open champion, 19, withdrew from his quarter-final against Rune in Paris with an abdominal problem and has now brought his stellar season to a premature end.
He wrote on Twitter: "After my withdrawal yesterday and having been evaluated by my medical team, unfortunately this is the result of my injury: an internal oblique muscle tear in the left abdominal wall with an estimated recovery time of six weeks.
"Unfortunately I won't make the ATP Finals or the Davis Cup Finals. It is tough and painful for me to miss these two events, which are so important to me, but all I can do is be positive and focus on my recovery. Thank you for the support!"