The women's French Open semi-finals will feature the two best players in the world - and two players who only dreamed of making it this far.
Australian Open champion Aryna Sabalenka plays unseeded Karolina Muchova, a player ranked outside the top 200 as recently as September, in the first semi-final on Thursday from 14:00 BST.
Then world number one Iga Swiatek, champion in 2020 and 2022, faces Beatriz Haddad Maia, who had never made it beyond the third round of a Grand Slam before this tournament.
There will be live commentary on both matches on the BBC Sport website and app.
Top two on course to meet in final
Swiatek, 22, and Sabalenka, 25, are seeded first and second respectively and have been considered among the favourites for the title since the tournament began.
Should they meet in the final then the world number one position would also be on the line with Swiatek's 62-week run at the top under threat.
Sabalenka would have overtaken Swiatek in the rankings if the Pole had lost her quarter-final on Wednesday, but she defeated American teenager Coco Gauff in two sets, just as she did in last year's final.
Swiatek has been in fine form at Roland Garros and not dropped a set in her five matches.
"I didn't spend too much time on court so I'm happy it was a tighter match," said Swiatek after her 6-4 6-2 win over Gauff.
"I'm pretty fresh and will be ready no matter what. Not having a day off was something I knew since the beginning of the tournament so I'm ready."
Sabalenka had lost in the third round at Roland Garros in the past three years but has now reached at least the semi-finals at all four Grand Slams.
"I'm super happy to be in another semi-final," said Sabalenka following her 6-4 6-4 quarter-final win over Ukraine's Elina Svitolina.
Having declined to attend open news conferences for her mental wellbeing after a series of political questions, Sabalenka resumed her regular media duties after that win.
Belarusian Sabalenka has been under pressure to distance herself from Belarus president Alexander Lukashenko, a close ally of Russia president Vladimir Putin and who is providing military support in the invasion of Ukraine.
Sabalenka said on Tuesday that she did not support Lukashenko "right now" or the war, adding: "I don't want to be involved in any politics. I just want to be a tennis player."
'I have nothing to lose'
Muchova, 26, made the last four at the Australian Open in 2021 and then the quarter-finals of Wimbledon before an abdominal injury kept her out for seven months.
She dropped to 235th in the world rankings and ended 2022 151st.
But she reached the quarter-finals of the WTA 1000 tournaments in Dubai and Indian Wells and claimed a huge victory over eighth seed Maria Sakkari in the opening round in Paris.
"It's been an incredible two weeks and I'm just glad I'm still in the competition," said Czech Republic's Muchova, who will return to the top 20 after the tournament.
While Muchova has made a Grand Slam semi-final, it will be a whole new experience for 27-year-old Brazilian Haddad Maia.
"My first goal was to be in the third round - I had never won a second-round match before in a Grand Slam," said Haddad Maia.
"When I won the third round, I said, 'OK, now I reach another goal'. Every step we pass through makes us stronger."
Haddad Maia, who served a 10-month doping suspension which ended in 2020, was involved in a near four-hour epic against Spain's Sara Sorribes Tormo in the last 16 before fighting back from a set down to beat seventh seed Ons Jabeur in the quarter-finals.
"It's not easy to be set down against Jabeur, and she was playing well," said 14th seed Haddad Maia.
"When the match was done, I looked to my team and said, 'we made it' - and I'm very excited for what is coming."
Haddad Maia beat Swiatek in their only previous meeting, on a hard court at the Canadian Open in Toronto in August, winning 6-4 3-6 7-5.
"She's the number one and one of the best players we have from the last year," said Haddad Maia.
"She's young, she's a nice person, she has already won twice here.
"I'll try to enjoy it and I'll try to play every single point. I'll leave everything on the court. I have nothing to lose."
What else is happening on Thursday?
Japan's Miyu Kato has the chance to end an eventful competition with a trophy as her and Germany's Tim Puetz play in the mixed doubles final against Bianca Andreescu from Canada and Michael Venus of New Zealand.
On Sunday, Kato, 28, was disqualified from the women's doubles after she hit a ball girl with a ball.
Kato offered her "sincere" apologies to the youngster for the "unfortunate mishap", saying it was "completely unintentional".
In the men's wheelchair singles, British top seed Alfie Hewett, a three-time champion at Roland Garros, plays in the semi-finals against third seed Gustavo Fernandez of Argentina.
Britain's Lucy Shuker is in women's wheelchair doubles action as she and American Dana Mathewson play French pair Pauline Deroulede and Emmanuelle Morch in the quarter-finals.