Kasatkina finally bowed out at Roland Garros on Monday, beaten by the 18-year-old phenom and her fellow Russian-born friend Mirra Andreeva 6-3 7-5 after what the victorious teenager rightly called a "hell of a match" in the fourth round at Roland Garros.
Two months since being granted permanent residency, Kasatkina's hopes of becoming the first Australian woman to reach the quarter-finals since Ash Barty's triumphant year of 2019 may have fallen short, but the 28-year-old, who enjoyed being the 'last Aussie standing', smiled: "It's been a good start.
"First of all it's been a good result but also, I felt super good to step on the court as an Australian player," said the 17th seed.
"To feel the support from the stands so many times. I don't know if everyone who was screaming, 'Aussie', were from Australia, but I felt this support. Also, on social media I'm getting a lot of support from the Australians that they are so happy to welcome me, and they're happy for me.
"So this is the kind of support which I honestly didn't have before, it feels like it's something new to me -- but it feels so nice."
When asked if everyone was now allowed to call her "an Aussie battler" after she had given the sixth seed a real scare with her second-set counter-attack when she even earned a set point, Kasatkina offered a wry smile and replied: "If you want to..."
It was a tremendous match full of variety, like blitz chess between two all-court grandmasters, played in a fabulous spirit by two training partners.
Their 94-minute duel on Court Suzanne Lenglen ended with Kasatkina chucking her wristband jokingly at her conqueror at the net, while Andreeva informed the crowd tongue-in-cheek that she only practised with the Aussie because she hated her.
All good knockabout stuff, though Kasatkina noted wryly: "Maybe we know each other too good, maybe we have to take a break in practising ... no, I'm kidding."
The only other time they'd played a match was in the final of last October's Ningbo Open in China, with Andreeva ending in tears and needing to be comforted by the player 10 years her senior after blowing a 3-0 lead in the final set.
Things have clearly changed. Andreeva has grown up. This time, she said it was easy to put friendship aside as she repelled Kasatkina's second-set surge when the world No.17 went from 3-1 down to 5-3 up, with a combination of the most extraordinary defensive resolve and some ferocious attacking shots.
All looked lost for Kasatkina at the start of the second, but she lived up to her promise that she was ready to "die on court" as she chased down seemingly impossible causes and even outlasted the youngster to win one remarkable 26-shot rally.
And that utter determination did give Andreeva problems as Kasatkina earned a set point on the youngster's delivery at 5-4, only to be deprived by a powerful forehand.
Once back level, Andreeva began to dictate. One piece of amazing retrieving also induced a dismal Kasatkina smash into the net, and enabled her to break to love, before she sealed the deal on her second match point when the Aussie hit a forehand long.
Andreeva has reached the quarters without dropping a set and is the youngest woman this century to achieve back-to-back last-eight appearances. Martina Hingis last did it in 1998.
Asked if her input in practice might have helped Andreeva mature, Kasatkina smiled: "I hope not!"
But she did recognise a completely different force to the Ningbo victim. "Well, she grew so much. I feel like she's taller and taller every single week, her serve's improving all the time and her movement is very good."
Australian interest remains strong around the grounds, with world No.2 junior Emerson Jones through to the second round of the girls' event with a 6-1 1-6 6-2 win over American Capucine Jauffret.
Olympic men's doubles champions John Peers and Matt Ebden beat Italian fourth seeds Andrea Vavassori and Simone Bolelli 6-2 7-6 (8-6) to make the quarter-finals.
