Zidansek, the first woman representing Slovenia ever to make a slam semi, and one-time junior Russian prodigy Pavlyuchenkova both hailed their own battling qualities for enabling them to prevail in nail-biting three-set marathons on Tuesday.

Former snowboard star Zidansek, ranked only 85 in the world, had moments when she looked on thin ice but reckoned she'd 'fought for her life' to overcome Spain's 33rd seed Paula Badosa 7-5 4-6 8-6 in two hours 26 minutes.

Up next on Court Philippe Chatrier, Pavlyuchenkova, who'd previously reached six slam quarter-finals but could somehow never get beyond, outlasted doubles partner Elena Rybakina in an even longer, more compelling marathon 6-7 (2-7) 6-2 9-7.

The 29-year-old Pavlyuchenkova, seeded No.31, admitted it was "mentally really hard" to beat the woman she'll be partnering in Wednesday's doubles quarter-finals as she looks forward to next facing Zidansek, six years her junior, in Thursday's semis.

Wednesday's other quarters also feature some unlikely faces with Greek No.17 seed Maria Sakkari facing champion and hot favourite, Iga Swiatek while Czech doubles specialist Barbora Krejcikova faces US teen sensation Coco Gauff.

"It feels overwhelming, sounds crazy," smiled Zidansek, asked how it felt to be in the last-four, having never been beyond the second round.

She looked as if she might have missed the boat when dominating at a set and 4-2 up, only to get seriously tight with the winning line in sight.

But Badosa, despite forging her way back into the contest by reeling off six games in a row to take early control of the deciding set, admitted she was caught up by nerves as Zidansek regrouped.

Playing the tournament of her life after another gutsy first round marathon defeat of No.6 seed Bianca Andreescu, Zidansek found her most redoubtable form at 6-6 in the final set, saving three break points before earning a critical hold.

Badosa then delivered another nervy game as Zidansek snatched two match points, taking advantage of the second by cracking her 48th winner of a remarkable encounter.

Maribor's Mima Jausovec represented Yugoslavia when she won Roland Garros in 1977 but 23-year-old Zidansek, a three-time junior national snowboard champ who gave up because it was too chilly a pastime, is the first to make the semis for an independent Slovenia.

Pavlyuchenkova has never stopped believing her time would come, 10 years since she first reached the quarters at Roland Garros as one of the rising stars of the circuit but blew her big chance against Italian Francesca Schiavone.

She swears she's a more accomplished, mature figure these days and though she got blitzed by the flat-hitting power of Kazakhstan's No.21 seed Rybakina in the opening set, just as Serena Williams had been blown away in the previous round, Pavlyuchenkova stayed calm.

"I knew what to expect from her. The only thing you can do is hang in there. I believed in my chances. I know I'm a fighter, so I will fight till the end. That's what I did," shrugged Pavlyuchenkova.

She stayed aggressive as the storm began to subside and looked the more solid of the two as Rybakina finally delivered a double fault for the tamest of endings to a two hour 33 minute battle.

Australian Associated Press