And his mood didn't change much once he got to the post-match press conference.
Tsitsipas was sent packing in straight sets by Medvedev, crashing out of the tournament in a 6-4 6-2 7-5 thrashing on Rod Laver Arena.
When asked what had made Medvedev so tough to beat, Tsitsipas seemed at a loss - yet somehow perfectly aware at the same time.
"Everyone saw what just happened out there - I'm the last person you should be asking this," he said.
"I was just focused on my game, and he put out his show.
"He became Daniil Medvedev for three sets in a row."
The Greek star then bristled at a reporter after being asked who he thought might win the final between Medvedev and Novak Djokovic.
"Look, I'm not a betting website. I don't know what to say," he said.
"I wouldn't be surprised to see Daniil win the tournament…I don't know.
"Like, Djokovic is playing well too. Might be Medvedev, would be good for him, good for tennis."
Tsitsipas 'blessed' to play at Australian Open
Luckily for the reporters, Tsitsipas lightened up a bit as he paid tribute to Australia.
"I created some amazing memories during that period - had a very nice stay in Australia," he said.
"Despite all the downsides on having to stay 14 days in the room, and few other things, generally speaking it was a hell of a trip here in Australia.
"And personally I'd like to thank everyone for putting out such an amazing event and show for the players.
"Not only for the players, but for all the agents, coaches, and crew that came to be part of this tournament and to represent the players."
With strong Greek support in the Victorian capital, Tsitsipas said he felt like he was at home.
It was no more evident than when he rode a wave of support to come from two sets down to beat Rafael Nadal in the quarter-final.
"I feel blessed when I'm playing here," he said.
"I feel like everything can only be seen from the bright side, and people are beautiful. It's a really nice place to play tennis.
"I'll miss it, for sure."
Medvedev's win extended his record against Tsitsipas to 6-1 and continued the 25-year-old's phenomenal 20-match unbeaten run on tour.
While world No.1 Djokovic will be a warm favourite to end that golden stretch as he seeks his ninth Norman Brookes Challenge Cup, the Serb is unlikely to hold any great fears for Medvedev, who has won three of their last four encounters.
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