She beat her Swiss opponent Timea Bacsinszky 7-6, 3-6, 6-3 to advance to Saturday's (June 10 final at Roland Garros in Paris.

Following a last eight win over Denmark's former world number one Caroline Wozniacki, Ostapenko became the first teenager to reach the penultimate stage of the Grand Slam event since 2007, when Serbia's Ana Ivanovic achieved the feat. 

Returning to the court as a 20-year-old, she has broken new ground today as the first unseeded player to reach the French Open final since Slovenia's Mimi Jausovec in 1983.

Jausovec eventually lost to Chris Evert of the United States 6-1, 6-2.

"I am really happy," said Ostapenko after her win on the clay.

"I love to play here, I love you guys, you're amazing.

"I'm just happy with the way I celebrated my birthday.

"I was always playing aggressive and hitting the ball when I had a chance.

"It probably helped me to win today."

Coincidentally, Bacsinszky also celebrated her birthday today, turning 28.

Ostapenko, ranked 47 in the world, will now play Romania's Simona Halep in the final.

The tournament's third seed beat Karolína Plíšková of the Czech Republic 6-4, 3-6, 6-3 to move to within one victory of a maiden Grand Slam win.

Czech second seed Plíšková would have become world number one next week had she won the second semi-final.

Now the opportunity to knock Germany's Angelique Kerber off top spot falls to Halep, who will become the world's highest ranked player if she beats Ostapenko in the final. 

Action is due to continue tomorrow with the men's semi-finals.

Austria's rising star Dominic Thiem will play Spain's Rafael Nadal in an eagerly anticipated match.

Thiem dumped out defending champion Novak Djokovic of Serbia yesterday while Nadal is aiming to win a record 10th title at the French Open.

Sir Andy Murray of Great Britain, the world number one, will meet Switzerland's Stan Wawrinka in a repeat of last year's semi-final in the other match.