The 19-year-old Queensland-based youngster, with two titles under her belt already this season, looked to have gone off the boil a little after winning the grass-court title at Eastbourne at the end of June.
But her 6-3 6-1 trouncing of world No.28 Kenin in the last-16 at the prestigious WTA 500 hardcourt tournament in Seoul on Wednesday demonstrated she's back to her best as she breezed into her fifth quarter-final of the 2025 campaign.
Apart from being broken in her opening service game, Joint dominated Kenin for the second time this season, just as she had done in the Hobart International in January by exactly the same scoreline.
In all, the world No.46 Joint broke seventh seed Kenin's serve five times before serving out to love for a dominant victory in five minutes over an hour.
It set up a last-eight date at the Olympic Park Tennis Centre for the teenager with Denmark's No.3 seed Clara Tauson, who beat German Eva Lys 6-2 7-6 (7-4).
The world No.12 Tauson defeated Joint in straight sets at the start of the year in a Canberra Challenger event but may find the American-born youngster a much more formidable prospect these days in Friday's quarters.
World No.20 Daria Kasatkina, the Australian No.1 who Joint is chasing, will also seek to make the quarter-finals in Seoul when she faces the ever tough Czech Katerina Siniakova in Thursday's last-16 clash.
As Australian players began to target several tournaments in south-east Asia, Chris O'Connell enjoyed a bright start to the Chengdu Open in China with his 6-7 (3-7) 6-3 6-4 first-round comeback win over Frenchman Quentin Halys.
The 31-year-old Sydneysider will next face 20-year-old Chinese prospect Yi Zhou, who pulled off the shock of the day by ousting fifth seed Cameron Norrie.
Jordan Thompson is also in the Chengdu field, and will open up against Chilean qualifier Alejandro Tabilo on Thursday.
At another Chinese event, the Hangzhou Open, Rinky Hijikata won his final qualifying match 6-2 7-5 against American Brandon Holt to join his Australian colleagues Adam Walton and Aleksandar Vukic in the main draw.