The 29-year-old came to the rescue after the 13-strong Aussie contingent's grass-court invasion began on a warm opening day with an injury-hit defeat for Aleksandar Vukic and a four-set loss for Roland Garros giant-killer Adam Walton.
Former quarter-finalist Kasatkina, the high-profile import who'd been the last Australian standing in Paris, had entered her ninth Wimbledon on the back of a winless grass-court campaign, admitting she had no great expectations of enjoying a deep run.
But after subduing a second-set fightback to beat the 18-year-old Welsh youngster Mimi Xu 6-2 3-6 6-2, Kasatkina was determined not to get too enthusiastic about her change of fortunes as she set up a second-round clash with Janice Tjen, who last year became the first Indonesian woman in 23 years to win a tour title.
"I wouldn't call myself favourite for that match," said Kasatkina, who's ranked No.65 to the Indonesian's 42.
"That's pretty much my approach for this tournament. Enter every match with low expectations, because the lower the expectations it's actually better for you.
"Well, cannot say that I was super happy with my level today, but the attitude was there and that was the most important thing. Really happy with my efforts, especially in the third set, because in the second she was playing way better than in the first. I was really happy how I was able to manage that."
Earlier, Vukic had become the first casualty, suffering a knee injury before bowing out 7-6 (9-7) 6-1 6-1 to a familiar US foe Jenson Brooksby, who'd also defeated him in Eastbourne last week.
Vukic had been hoping for a decent run at the slam where he had the fortune - and misfortune - to play Carlos Alcaraz and Jannik Sinner in the past two years, knowing a run to the third round would likely earn him another crack at the Italian reigning champion after being filleted by him in straight sets in 2025.
World No.104 Vukic had his chances in a tight opening set, racking up a couple of set points as he led 6-4 in the tiebreak, only for Brooksby to save the first stanza with an audacious drop shot before prevailing on his fifth set point.
Then the problems began for Vukic. Beginning to move less easily, he ended up needing a medical time-out after being outplayed in the second set, with things worsening in the third as the Sydneysider reported: "It's an MCL strain, the same issue I had in Birmingham a few weeks ago ,but I don't think it's anything serious."
Walton, the Queenslander who'd enjoyed the best win of his career when knocking out former world No.1 Daniil Medvedev at the French Open, enjoyed an excellent start against Croatian Dino Prizmic, taking the first set, but fell away after losing a second-set tiebreak, eventually succumbing 4-6 7-6 (7-3) 6-4 6-2.
The differing fortunes from Paris has spelt bad news for Walton, who reckoned: "I'm on the cusp of the cut to get into the US Open cut and just need to keep playing the next two weeks to give myself every chance to try and make the main draw."
The fourth Australian in action, Rinky Hijikata, was on the verge of grabbing the third set of his close-fought duel with Dutchman Jesper de Jong, leading 6-7 (4-7) 6-3 5-3 when the court dew and fading light just before 9pm local time forced the players off.
