Well, it could go either way technically, but realistically, it will go the way of Djokovic. There are several reasons why; we'll go through them in order, but first, let's see how they played recently.
He will always be dangerous indoors because of his serve, but in the rallies, the Greek traditionally struggles against Djokovic. He can do some serve and volley, but eventually, Djokovic will get used to it.
After all, Djokovic leads 11-2 in this matchup, and the only two wins Tsitsipas has happened in 2019. He's not beaten him in four years, losing to him ten straight times. Some of those matches were close, of course, but he was never really close to beating him.
There is just very little Tsitsipas can do in this matchup that Djokovic doesn't have a solution for.
So, when we look at all those things and the current form of both players, it's pretty clear that Djokovic should have the upper hand. The Serbian has also been very good in Turin, going undefeated last year to win the trophy.
He did have some tough matches in Paris but I trust that he'll recover pretty well for this event here. He kind of paced himself in Paris as well, which is nothing unusual.
I expect him to be at his best here, and there is very little Tsitsipas can do against peak Djokovic. He'll try a few things here and there, but as the H2H shows, all of them fail pretty consistently.
Prediction: Novak Djokovic to win in two sets.