Can I pick Match does not complete due to retirement?
Just kidding, I'll go with Djokovic in 5. I got to believe at some point, Djokovic has that one last good performance left in him, like Roger did at 2019 Wimbledon (see semifinal match against Rafa).
Jannik takes the first set in 38 minutes. Not sure what Djokovic can do here. I think Courier is right, he'll have to take big risks and come way out of his comfort zone. I remember the US Open 2010 when he was getting manhandled by Nadal. He managed to do it in the second set but it took a Herculaneum effort and it was highly unlikely he was going to retain that level (and didn't).