Match point won, he doesn't yell or exult. Doesn't pump his fist or raise an arm. Just stands on the baseline, hands on hips. Holds the pose. With a look that's somewhere between "what the hell" and "look at me now". The history kid from Korea.
Maybe, of course, Chung Hyeon stands there in relief, grateful that the final game - 14 points, five match points, two break points, one 31-shot rally - is finally over. Maybe it's disbelief that he, just another boy with another dream, has beaten Tennys Sandgren 6-4, 7-6 (7-5), 6-3 and reached the Australian Open semi-finals.
Maybe he looks at the stats sheets, which say a 21-year-old is the first South Korean in a Grand Slam semi, the youngest man in a Slam semi since Marin Cilic in 2010, the lowest-ranked player, No. 58, in an Open semi since Marat Safin in 2004, and thinks: That's me?
Maybe he, who writes in Korean on the camera lens, "Chung on fire" is the story of this Open. Not just because he wins but because the calm with which he wins. After the match I meet Se Yun Hong and June Choi, who have travelled from Korea for the Open and I ask, what do you like? "His mentality," they echo. "His commitment and calm."
Indeed, during a changeover, Rod Laver enters his Arena, and his presence is announced and he waves and people stand and cheer, but Chung stares straight ahead. In a brilliant bubble. Glasses cleaned and mind clear. But so much history-making, isn't he tired? "I think I'm not tired because I win. When I win the match against top player, never tired. Just happy, no?"
Reporters laugh. Then they chuckle when he is asked, "How many sponsors do you have and do you think your agent will be very busy after the tournament?" and he turns to his agent Stuart Duguid to understand the question precisely and once he does, he smiles and says: "I hope. I hope they busy, yeah."
Maybe this is also why people take to him, why the crowds hail him, because unlike so many Asian athletes he's letting us see who he. Relaxed. Normal. Funny. He may be learning English but he has a degree in charm. Neville Godwin, the ATP coach of the year in 2017, who joined Chung not even two months ago, told The Straits Times: "He's done a fantastic job of letting his personality and character come out."
Maybe today wasn't a great match, just "nervy" as Godwin described it, because for the first time Chung, No. 58, was favourite since Sandgren is No. 97. But the match was a test that is so often failed in sport, wherein an upcoming player rises to topple a top player, as Chung did to Novak Djokovic, but then is emotionally empty for the next round. But Chung did not fail. He was not at his best against Sandgren but he was simply better.
In the afternoon, 20 minutes before his match, I passed him in a hallway, on the way to a treadmill. In a way he's always running for his life. During the match he would play six long rallies - 21 shots, 37, 17, 25, 25, 31 - and win five.
On court Sandgren got a cheer, and Chung a roar, and then an Evacuate alarm went off but he reacted as he does to break points. No fuss. In a sport full of twitchers and fiddlers, he's a man of economy who just tugs at his shirt at the shoulders, hitches his shorts and is ready.
The first set takes a quiet 31 minutes, 6-4 for Chung, the second has four breaks and Sandgren serves for the set at 5-3 but Chung breaks back, forces a tie-breaker and grabs it. It's a compelling win for his life is altering right before us, his status in his homeland rising, TVs being put on just for him, and as Godwin says "the hunter becomes the hunted".
Maybe it requires a strong character to handle this but he comes from a nation of solid sporting ones. We're so enamoured by European footballers and addicted to American stars that we forget that closer to home champions roam.
Korea has won 27 women's golf Majors, all eight women's archery Olympic team golds ever contested, 21 short track speed skating Olympic golds, has hall of fame boxers, a World Cup football semi-final place and a male golfer who did what no one had, beat Tiger Woods from behind.
Maybe one day Chung will be in this company but it will take time and adjustment. He and Godwin have already tinkered with his service action - feet more together - and he requires more power off the ground and journeys to the net. But that is for some other day. This was like no other day.
For a brief moment in that last game even he thought, "If I win one more point, I make history in Korea." Coaches always say stay in the present, but sometimes a young athlete can be stirred by the future he is just about to make.
And then maybe shaken by the past he is about to meet. In the semis, Federer awaits.