American teenager Amanda Anisimova has reached the semi-finals of the French Open with a straight sets win over defending champion Simona Halep.

Romanian third seed Halep, 27, lost 6-2 6-4 to the unseeded 17-year-old.

Anisimova had never won a match at Roland Garros before this year but is yet to drop a set on the way to her first Grand Slam semi-final.

The world number 51 will face Australian eighth seed Ashleigh Barty, who beat American Madison Keys 6-3 7-5.

"This is honestly more than I could ever have asked for," said Anisimova on court after the match.

"That was one of the best matches I have ever played."

As well as winning her solitary Grand Slam title in Paris, former world number one Halep, 27, was runner-up at this tournament in 2017 and 2014.

But her defeat means there are no Grand Slam champions left in the women's draw.

Who is Anisimova?

Anisimova is one of two teenagers in the last four as Czech 19-year-old Marketa Vondrousova will face Britain's Johanna Konta in Friday's semi-final.

The defeat of Halep is not Anisimova's first upset at Roland Garros. She also beat 11th seed Aryna Sabalenka in straight sets in the second round.

The American missed the entire 2018 clay season with a right foot injury but has made up for it this year, winning her first WTA title in Bogota two months ago.

That made her the youngest American to win a tour title since Serena Williams did so aged 17 at Indian Wells in 1999.

Anisimova's previous longest run at a Grand Slam came at her maiden Australian Open earlier this year, where she reached the fourth round.

If she goes on to win the title, she will become the first teenager to win a Grand Slam since Maria Sharapova won the 2006 US Open aged 19.

Halep on the ropes from the outset

Anisimova got the first break of the match, to lead 4-2, after forcing Halep to hit the ball long as she was pinned back behind the baseline.

Halep had a break point in the next game, but Anisimova held and broke Halep's serve once more to win the first set in 28 minutes.

Despite Halep hitting an 80mph winner, Anisimova broke again to take a 2-0 lead at the start of the second set.

As chants of 'Simona' broke out on Philippe-Chatrier, Anisimova saved three break points to hold serve and lead 4-1.

Halep eventually broke back as the American hit a ball long, but a double fault at 5-4 down brought up match point and former French Open junior finalist Anisimova kept her composure to win just her eighth match at a Grand Slam.