A clinical Ashleigh Barty blew away Madison Keys at Roland-Garros to earn her first grand slam singles semi-finals spot on Thursday night.

The eighth seed made light work of the 14th seeded American 6-3 7-5 on Court Suzanne Lenglen in little more than an hour.

Barty, whose previous best was reaching the Australian Open quarter-final in January, served for the match at 5-4 but Keys broke the Australian for just the first time in the match.

A crucial double fault by Keys gave the 23-year-old Queenslander an immediate break back.

First Grand Slam semi-final!

@ashbar96 takes out Madison Keys 6-3 7-5 for a place in the Roland-Garros semi-finals.

🎾 https://t.co/VDCaFTPx5U#RG19 pic.twitter.com/0lE8boAwGU

— Roland-Garros (@rolandgarros) June 6, 2019

Barty then served out the match to love to move within two wins of the French Open singles title.

She will next play Amanda Aminisova, of the United States, who defeated former world No.1 and third seeded Simona Halep 6-2 6-4 earlier on Thursday (local time).

Aiming to become the first Aussie in the semi-finals at Roland-Garros since 2016…

Ash Barty takes the first set 6-3 over Keys.

🎾 https://t.co/VDCaFTPx5U#RG19 pic.twitter.com/T0AcdSlZQm

— Roland-Garros (@rolandgarros) June 6, 2019

“I took my one opportunity that I got in the first set, and it’s just amazing,” Barty told on-court interviewer Fabrice Santoro after the match.

“I feel like I played great tennis and I’m happy to be through.”

Admitting she was surprised “very much so” to reach her first grand slam semi, Barty said it has been an amazing tournament.

“I’ve been learning every single day about clay court tennis. I’ve been enjoying it. I’ve been loving it and I’m really excited that I get another chance to play in a semi-final,” Barty said.

Madison Keys had no answer to Barty’s variety in the straight-sets loss. Photo: Getty

Barty said she was looking forward to play the 17-year-old American, adding she hadn’t “seen much of her in general and I haven’t played against her”.

“So it’s a clean slate for both of us and an exciting opportunity for all four of us that are in the semis,” she said.

“I know we are all very excited. It’s just an amazing situation to be in.”

Barty has tasted grand slam doubles success with Coco Vandeweghe at the 2018 US Open, having reached finals with fellow Australian Casey Dellacqua in 2013 (Australian Open and Wimbledon) and at the French Open (2017).

Victory for Barty will move her to third in the world rankings and she’ll rise to second if she lifts the Coupe Suzanne Lenglen on Saturday.

Success in Paris would also see her become the first Australian since Margaret Court in 1973 to win at Roland Garros.

She would also become the first Aussie to clinch a grand slam title since Samantha Stosur’s US Open triumph in 2012.

With 26th-seeded Sydney-born Brit Johanna Konta the only player left in the draw with a top-30 ranking, Barty will never have a better chance to break her grand slam duck.

But she believes rankings mean little when so much is at stake at a grand slam.

“All four of us have been playing great tennis,” she said.

“It’s a new situation for me. I don’t think you know quite what to expect tomorrow, but I will prepare and do the best that I can to keep it normal.

“Obviously it’s a little bit of a different buzz and a little bit of a different electricity.

“But, ultimately, I’ll try and prepare and do everything exactly the same and try and play my best tennis.”

Barty’s match and Konta’s clash with unseeded Czech Marketa Vondrousova both begin at 11am local time (7pm AEST) on Friday.

-with AAP