Continuing Greece's dream slam following compatriot Stefanos Tsitsipas's march into the men's semis, Sakkari was outstanding in her 6-4 6-4 triumph over the Polish teenager on Wednesday as she also roared into the last-four.

After being overpowered in the opening set, the champion and overwhelming tournament favourite Swiatek, clearly nowhere near her best, needed a medical timeout at 2-0 down in the second.

Struggling for her usual timing and with her forehand betraying her as Sakkari targeted it relentlessly, Swiatek returned from off-court treatment with a heavily strapped right thigh, hoping to halt the domination of the powerful 25-year-old from Athens.

But still seemingly struggling with her rotation, Swiatek was unable to make any inroads into her opponent's serve, which had held firm after being broken first time out in the opening set.

"I'm speechless. It's a very nice feeling. We still have a long way to go but we made a huge step today," the beaming Sakkari said on-court afterwards.

"I just really enjoyed today and before coming into the match today, I just sat down by myself and told myself, 'you know what, it's a very important match but just enjoy it because this is one of the best stadiums in the world.' I had to enjoy it."

Sakkari's performance, against a player who was on a remarkable Roland Garros-winning roll of 11 matches and 22 sets, was out of the top drawer after her slightly nervy start.

The player who's bloomed later in her career cracked 26 winners and won 83 per cent of the points whenever she got her first serve into play.

After Barbora Krejcikova had earlier on Wednesday ended teenager Coco Gauff's Roland Garros run with a 7-6 (8-6) 6-3 win, it meant, remarkably, that all four women who've made Thursday's last-four will be in their maiden grand slam semis.

So an unlikely new champion will be crowned on Saturday.

Amid the quartet, Slovenian world No.85 Tamara Zidansek will play Russian 31st seed Anastasia Pavlyuchenkova while Krejcikova, a five-time grand slam doubles winner who'd never been beyond the fourth round in the singles, will take on 17th seed Sakkari.

Australian Associated Press