"I had opportunities," the 20-year-old Australian recalls of his four set loss. "I won the first set and was up a break in the third. I took him to four."
At the time, Medvedev was the 11th ranked player in the world. A rising talent with a bright future on the ATP tour.
Six months later, and after a breathtaking run during the North American hard court season in which he made four consecutive finals, the Russian has shot up to world No. 4. Many are now tipping him as the man most likely to end the 'Big 3' dynasty.
On Saturday, Popyrin and Medvedev will meet again at Grand Slam level, this time in the third round of the Australian Open.
Popyrin is fully aware of what's coming his way, but has warned Medvedev he's a vastly different player to when they first faced off six months ago on the grass courts of England.
"I'm a better player right now than I was at Wimbledon," Popyrin claimed after his second round, straight sets win over Spain's Jaume Munar. "I've gotten a lot of experience last year and I did a lot of work in pre-season. I'm not star-struck by being in the third round anymore. I'm more self-centered and focused.
"I'm going to look to play my game, be aggressive and on the front foot. Hopefully I get the chances I had at Wimbledon last year and convert them."
It's not going to be easy to overcome Medvedev, someone Popyrin rates as "the hottest player you could get right now".
Medvedev, the 2019 US Open runner-up, has already dispatched American Frances Tiafoe and Spain's Pedro Martinez Portero en route to the last 32 at Melbourne Park, and is the fourth favourite with bookmakers to win the entire tournament.
"He's one of the best players in the world," Popyrin said of Medvedev. "Hard court is probably his favourite surface and [when he's playing well] he's just not missing.
"He can stand on the baseline and just get every single ball back. He also creates opportunities for himself. Not many people can rally with him on the baseline. He's probably the best."
It's not just Popyrin who remembers the encounter in Wimbledon. Medvedev also recalls the "exhausting" match out on Court 12.
"It was a really tough match, an exhausting one," Medvedev told reporters in Melbourne. "Last Australian Open we saw how he can play in Grand Slams in front of the home crowd. It's not going to be easy."
Popyrin's already making a name for himself as a giant killer. In 2019, he was responsible for sending fifth seed Dominic Thiem packing, while this year he's already got the better of former Australian Open finalist and boyhood idol Jo-Wilfried Tsonga.
Will Medvedev be his next victim?