US Open champion Sloane Stephens beat Daria Kasatkina to reach a first French Open semi-final and set up a meeting with fellow American Madison Keys.
Stephens, who beat Keys in last year's US Open final, defeated the Russian 6-3 6-1 at Roland Garros in Paris.
Keys saw off Yulia Putintseva to also reach the last four of the French Open for the first time.
She overcame the unseeded Kazakh, who defeated Great Britain's Johanna Konta in the opening round, 7-6 (7-5) 6-4.
Kasatkina knocked out second seed Caroline Wozniacki on Monday but was unable to get the better of world number 10 Stephens as the 25-year-old progressed in one hour and 10 minutes on Court Philippe Chatrier.
"I'm excited to play my good friend in the semi-finals, we've already played in the US Open final and it's really good for American tennis," said Stephens.
Earlier, Putintseva held a 5-3 lead and served for the first set against Keys, before the 13th seed fought back to win it in a tie-break.
Keys then broke Putintseva's serve in the seventh game of the second set to extend her best run at the French Open.
"Honestly, the (US) Open feels like it was 12 years ago at this point," said Keys, who won only three games against Stephens in the final at Flushing Meadows.
"I obviously rely on what I learned there and how to manage my emotions and manage the moment, but there were so many late nights and I was so tired. It feels completely different here."