But with a wide open men’s draw devoid of a former Grand Slam winner and the tantalising prospect of a first Major title, he came unstuck in the quarter-finals against another Russian, Karen Khachanov.
Like Medvedev, Khachanov had been sidelined at Wimbledon when Kyrgios made his run to the final and, having never made it past a Grand Slam quarter-final before, he was not expected to push the Australian the distance.
But in a thrilling five-set match which had everything from smashed rackets to two spectators being evicted for a bizarre haircut stunt, Khachanov won 7-5, 4-6, 7-5, 6-7, 6-4.
Another late finish in New York came to a close just a minute before 1am, Kyrgios marking the loss by smashing up two of his rackets and promptly exiting the court as his opponent lapped up the enormity of his breakthrough win.
“I did it, I did it,” Khachanov said afterwards. “I’m really proud of myself, I was focused from the beginning to the end. It was a crazy match but I came ready to fight and to play five sets.
“I stayed there. I waited for my chances, I created them. I’m super happy, super proud that I could finish the match. I could take it. I am just super happy to do this step forward to make my first semi-final.”
Unsurprisingly, it proved a big-serving contest — Khachanov rifling down 30 aces to Kyrgios’s 31 — and one which ebbed and flowed.
Surprisingly, though, for a match involving Kyrgios, it began devoid of any great atmosphere, as a relatively muted Kyrgios needed treatment on his knee after losing the first set.
“I can’t walk without pain,” he complained, and later screamed at his box: “I don’t want to f****** play through this s***.” His moaning appeared to have the desired effect, and he hit back to level the match, only for Khachanov to take the third set.
Again, Kyrgios reacted angrily, smashing a water bottle in frustration, which sparked him into life, and he won a fourth-set tiebreak to take the match to a decider.
Kyrgios will be left to rue his missed opportunities, of which there were plenty. He converted just two of nine break-point chances, while Khachanov took four of a possible eight break points, most crucially in the opening service game of the fifth set.
His opponent threw everything at him to try to break back but could not find the opportunity. Khachanov now faces Casper Ruud for a place in a first Grand Slam final for either man.
Kyrgios said: “I’m obviously devastated but all credit to Karen. He’s a fighter, he’s a warrior. He served really good today. Honestly, probably the best server I played this tournament. He played the big points well. Really wasn’t anything in it. I feel like I’ve just failed.”
Coco Gauff’s hopes of making a second Grand Slam final of the season were thwarted by Caroline Garcia, as the 18-year-old was knocked out 6-3, 6-4. Garcia now faces Ons Jabeur. who beat Ajla Tomljanovic 6-4, 7-6.