It was sad to see Tsitsipas lose the way he did after coming from behind to beat Nadal. It just shows that Tsitsipas still has a lot to learn when it comes to winning mentality and being more of a consistent player. I also felt sorry for Tsitsipas as everyone was commenting on his shorts with all the sweat which wasn't a good look but its not his fault and Nike need to work on making them better, or maybe change the colour.
It seems though that he was fatigue with his match against Nadal. And Medvedev played a tactical game here, he say that Stepanos was tired and take advantage of it, and then he had some shots that make Tsitsipas guessing throughout the game, very good tennis IQ.
I read that Medvedev has now won 20 matches in a row and if he wins the AO final it will make it 21 in a row which I find interesting as I'm a numbers guy so my theory is that Medvedev wins and makes it 21 matches in a row to win the first grand slam in the year 2021. Just as I said Nadal and Federer would both be on 20 grand slams each in the year 2020.
And he will overtake Nadal in the rankings as well, first time to see a player breaking Djokovic, Nadal, Federer and to some extent Murray to win a Slam. So there's a lot of weight on his shoulder against Djokovic, who suddenly feels great after a supposedly abdomen injury in the third round.