Wozniacki suffers at the hands of teenage star Jelena
Unseeded Latvian teenager Jelena Ostapenko fought through rain delays to battle past former world number one Caroline Wozniacki and secure a place in the semi-finals of the French Open at Roland Garros, but there was disappointment for home favourite Kristina Mladenovic.
Ostapenko (19), struggled against the wind during the opening set on Suzanne-Lenglen, which Wozniacki took control of with early breaks for a 5-0 lead.
Although Ostapenko, ranked 47 and looking to reach a first Grand Slam semi-final, recovered to 5-4 with two breaks of her own, the Dane closed out the first set as she broke the Latvian to love in the next game.
However, Ostapenko responded in the second set, breaking the world number 12 twice as she moved 5-2 ahead before rain.
After a delay of the best part of three hours, the teenager closed out the set on her serve to level.
Wozniacki, who has never made the semi-finals of the French Open, led 2-1 again in the decider before more rain.
Ostapenko, though, produced the required resolve when play resumed, with a double break putting her on the brink of victory, which she delivered when holding her serve to love for a 4-6 6-2 6-2 win over the 11th seed in just under two hours on court.
There was, though, tears of disappointment over on Philippe-Chatrier, where Mladenovic's hopes of becoming a first French champion since Mary Pierce in 2000 vanished in defeat to Swiss number 30 seed Timea Bacsinszky 6-4 6-4.
Ostapenko and Bacsinszky are set to meet for a place in the final on Thursday - which will be a birthday for both players.
Bacsinszky (27), the world number 31, had opened up a 2-0 and then 4-2 lead in the first set, only for Mladenovic to respond each time before closing out the set in 63 minutes with an ace.
Mladenovic briefly gave the rain-hit home crowd hope when she moved 3-1 ahead in the second set, only for Bacsinszky to recover with two breaks to lead 5-3 before closing out victory in one hour and 51 minutes.
French hopes now rest with Caroline Garcia, who faces world number three Karolina Pliskova today, while Elina Svitolina of the Ukraine plays Romania number three seed Simona Halep.
Yesterday's scheduled men's quarter-finals involving Novak Djokovic and Rafael Nadal were postponed until this morning.
Number two seed Djokovic will play Dominic Thiem of Austria on Suzanne-Lenglen, while Nadal meets Pablo Carreno on Philippe-Chatrier.
World number one Andy Murray plays number eight seed Kei Nishikori of Japan, and third seed Stan Wawrinka takes on Croatia's Marin Cilic.