The 23-year-old Anisimova, seeded 13, always had the favourite on the run as her clean power-hitting earned her a famous 6-4 4-6 6-4 victory and booked a date against either Iga Swiatek or Belinda Bencic in Saturday's final.
It was the first time in six years, since was considered one of the game's wunderkinds at 17, that the New Jersey star Anisimova had made it to the last-four of a grand slam.
On that occasion back in 2019, she held a set and a 3-0 lead over Barty at Roland Garros only to collapse on the home straight and allow the Australian to battle back and eventually not only win that match but the entire tournament.
On Thursday, though, she was much better equipped to prevail after a long journey back to the top which had featured her taking a year's break from the sport in May 2023 because of burn-out, when admitting that she was struggling with her mental health.
There were moments on Thursday when she still looked as if the pressure might be getting to her again as she lost the second set and saw her dominant 5-2 lead in the second pegged back to 5-4 while squandering a match point.
But she again raised her game as Sabalenka served to stay in the match, missing out on two further match-point opportunities before prevailing after two hours 36 minutes in a terrific semi-final.Â
"This doesn't feel real right now," she said. "I don't know how I pulled it out."
For Sabalenka, who replaced Swiatek at No.1 in October as the world No.1, this defeat prevented her from becoming the first woman to reach four consecutive slam finals since Serena Williams a decade ago.
But Anisimova could celebrate being the first American player since Williams six years ago to make the Wimbledon final.