PARIS — Jelena Ostapenko is a young woman in a hurry.

On the day she turned 20, Ostapenko became the first unseeded French Open finalist since 1983, using big and bold groundstrokes to end points lickety-split on the way to beating 30th-seeded Timea Bacsinszky of Switzerland 7-6 (4), 3-6, 6-3 on Thursday.

“Her life is like this: Everything very fast,” said Ostapenko’s coach, former pro Anabel Medina Garrigues. “Hit fast. Walk fast. Talk fast.”

It’s true. How quickly did this come together for Ostapenko, the first tennis player from Latvia to reach a Grand Slam final? Not only is this just her eighth major tournament, and not only had she never been past so much as the third round at one before this week, and not only did she lose her opening match in Paris a year ago, but she has yet to win a tour-level title of any sort.

“I mean, when I came here,” Ostapenko said, her words spilling out with nary a pause in between, “of course I didn’t expect I would be in the final.”

In Saturday’s championship match, No. 47 Ostapenko will face Simona Halep of Romania, who got past 2016 U.S. Open runner-up Karolina Pliskova of the Czech Republic 6-4, 3-6, 6-3 in the second compelling semifinal on a sunny day with the temperature touching 81 degrees.

The men’s semifinals begin Friday. In the opening match Rafael Nadal takes on Dominic Thiem. Top-seeded Andy Murray meets Stan Wawrinka in the other match.

While Ostapenko is assured of making her debut in the top 20 next week thanks to her surprising showing at the French Open, there is more at stake for the No. 3-seeded Halep: In addition to a chance for Grand Slam title No. 1, a victory would allow the 25-year-old to seize the No. 1 ranking for the first time, too.

This is the second major final for Halep, the runner-up to Maria Sharapova at Roland Garros three years ago.

There will be quite a contrast in styles Saturday.

The 5-foot-6 Halep is a ball-chasing, defensive dynamo unafraid of lengthy exchanges who gets to nearly everything off an opponent’s racket and is careful when she swings. She made 14 unforced errors against the No. 2-seeded Pliskova, whose total was 55. The 5-10 Ostapenko, meanwhile, is aggressive as can be, a go-for-the-lines-and-hit-them tour de force who likes to keep points as snappy as her answers to reporters’ questions.

Bacsinszky’s scouting report on Ostapenko, a pal she played doubles with last year?

“She is young and reckless, in a sense. She’s not afraid of anything. She’s a big hitter,” said Bacsinszky, who also lost in the 2015 French Open semifinals. “She’s a baby, but she’s a beautiful baby.”

One who hits the ball as if she’s angry at it.

Bacsinszky – whose birthday was also Thursday; she turned 28 – employed all manner of strategies in a bid to throw off her opponent. She tried staying in points until Ostapenko would make a mistake. She tried mixing speeds and angles and target spots. She tried hitting shorter to draw Ostapenko forward. She tried hitting deeper.