Defending champion beaten in straight sets; Serena avoids upset by compatriot Sloane.
Ana Ivanovic advanced to the semi-finals of a major tournament for the first time since winning her only Grand Slam title at the French Open seven years ago with a 6-3, 6-2 win over Elina Svitolina.
The Serb, who lifted the Suzanne Lenglen Cup in 2008, shrugged off the windy conditions to set up a meeting with Czech Lucie Safarova.
Ivanovic took control early on and never allowed her 19th-seeded opponent into the contest on Court Philippe Chatrier.
She put an end to a one-sided encounter on her third match point with a forehand passing shot to reach the last-four of a grand slam for the first time since 2008.
“I don’t know if I should feel old or happy,” the 27-year-old told a courtside interviewer.
“The only thing I could do was stay calm. The ball was going all over the place.”
Safarova, meanwhile, beat 21st-seed Garbine Muguruza Blanco 7-6, 6-3 to reach the semi-finals for the firrst time at Roland Garros.
“First time is ‘wow,'” Safarova said. “I’m so excited. Amazing.”
She also was a semi-finalist at Wimbledon last year.
13-Lucie Safarova (Czech Republic) beat 21-Garbine Muguruza Blanco (Spain) 7-6(3) 6-3
7-Ana Ivanovic (Serbia) beat 19-Elina Svitolina (Ukraine) 6-3 6-2