Australian eighth seed Ashleigh Barty and Czech teenager Marketa Vondrousova, the world number 38, will bid to win their maiden Grand Slam title in an unlikely French Open final on Saturday.
Play between Barty and Vondrousova, 19, is due to start at 14:00 BST.
Barty, 23, who quit tennis to play cricket in 2014, described reaching a Slam final as "crazy".
After becoming the first teenage Grand Slam finalist since 2009, Vondrousova said: "It is the best week of my life."
Vondrousova has not dropped a set in the tournament and ended British number one Johanna Konta's run with a 7-5 7-6 (7-2) win in their semi-final on Friday.
She has become the first teenage finalist at Roland Garros since Serbia's Ana Ivanovic in 2007.
Vondrousova and Barty have the youngest combined age of two female Grand Slam finalists since the 2008 French Open when Ivanovic beat Dinara Safina.
The pair have met twice before in tour-level matches, Barty not dropping a set in victories on the grass in Birmingham in 2017 and the Cincinnati hard court last year.
Barty aiming to cap her 'incredible journey'
Barty's first Grand Slam final comes almost three years to the day since she reappeared in the WTA rankings - at 623rd - after taking a break from the sport for more than a year to play professional cricket.
The Queenslander retired in 2014 and played for the Brisbane Heat in the women's Big Bash after saying tennis was a "lonely sport".
But she decided to return 17 months later and has since won four tour titles, including the biggest victory of her career at the Miami Open in March.
Now she is the first Australian woman to reach a first Grand Slam final since Sam Stosur at the US Open in 2011.
"It is crazy, it really is," Barty said.
"It's been an incredible journey the last three years. It's been an incredible journey the last two weeks.
"I feel like I have played some really good tennis, some consistent tennis."
Barty has the richer pedigree of the two finalists, having climbed into the world's top 10 after reaching her first Grand Slam quarter-final on home turf in Melbourne in January.
Her exploits at Roland Garros mean she is assured of a ranking inside the top five when they are released next week, with the number two spot awaiting if she succeeds on Saturday.
Seven-time Grand Slam champion Evonne Goolagong Cawley was the last Australian woman to be ranked as high as second - in December 1976.
"My team and myself have worked so hard to put ourselves in these positions. Now we get to go out there and really enjoy it," Barty added.
"That's the only way to approach it is to go out and enjoy it, have fun, try and play with freedom.
"That's ultimately when I play my best tennis and that's what we are after in the final."
Vondrousova 'never imagined' reaching the final
Vondrousova had only reached the second week of a Grand Slam once before this tournament - at last year's US Open - but has eclipsed that with her scintillating run at Roland Garros.
The left-hander has enjoyed a fine year after reaching the Hungarian Open and Istanbul Cup finals, along with quarter-final runs at more prestigious tournaments in Indian Wells, Miami and Rome.
Victory over Konta was her 15th victory on the clay this year, a tally only matched on the tour by the Briton and Croatian 31st seed Petra Martic - who Vondrousova beat in the Roland Garros quarter-finals.
"It's amazing. I never imagined this, I'm just very happy with everything," she said.
Vondrousova, who keeps opponents guessing by playing with plenty of variety, has won a tour-high 27 matches since January's Australian Open.
If she beats Barty then she will climb to a career-high ranking of 11, with a place in the top 20 already assured.
"I'm having so much fun on court. I'm playing good," said the Czech, who is the first teenage Grand Slam singles finalist since Caroline Wozniacki was runner-up at the 2009 US Open at the age of 19.
"It's really amazing when you're playing like this and winning all the matches. It's huge."