France's Kristina Mladenovic in action during her quarter final match against Switzerland's Timea Bacsinszky during the French Open on June 6, 2017. [Photo/Agencies]

Wind also posed great challenge to the tournament, as its speed reached as high as 9m/s. Four women's singles quarter-finalists on the courts found it pretty hard to concentrate on their matches, as they could not keep their eyes open.

"At the beginning it was really windy and tough for me to get my game, because I couldn't expect where the ball was bouncing," admitted Ostapenko, who moved into the semifinals at a Grand Slam tournament for the first time in career after the Latvian beat Caroline Wozniacki of Denmark 4-6, 6-2, 6-2.

"When I came here, I didn't expect that I'm going to be in the semis, but I was playing better and better every match. If I keep it up, I think anything can happen," she added confidently.

The 11th-seeded Wozniacki took five games in a row into the matchup against Ostapenko, while the latter responded with a four-game winning streak to cut the deficit within 4-5. Then the Dane finished a crucial break in the 10th game to take away the first set 6-4.

Ostapenko, who built a 5-2 lead in the second set before the rain, continued her in-form performance to force a decider.

Swiss Bacsinszky also won the first set 6-4 against local favorite Kristina Mladenovic on the Philippe-Chatrier Court when the rain began to pour down around 3:27 pm local time. The organizing committee announced that the game would resume at 4:45 pm, but that has been changed three times until 6:30 pm local time.

After a three-hour suspension, the two matches were halted once again by a brief rain around 7 pm.

After the second restart of the match, Bacsinszky sealed her place in the semifinals for the second time in three years with a 6-4 victory in the second set. She finished a total of three aces and 25 winners, nine more than her French opponent.

"Probably the experience of being already twice in the quarter-finals and made it even to the semi-final once helped me a lot, especially today," said Bacsinszky.

Ostapenko, to be 20-year-old on Thursday, also seemed to benefit from the rain delay as she beat Wozniacki 6-2 in the decisive set.

"Maybe this one is one of the best ones (birthday gifts). To play in the semi-final of Roland Garros on your birthday, it's really nice," said Ostapenko.

Wozniacki admitted she had a difficult match.

"She goes for her shots. Her shots are hard to read, so you don't really feel comfortable at any point in the match.

"You think that she won't be able to do crosscourt or down the line in certain moments, but she does it anyway," commented Wozniacki.

Men's singles title favorites Rafael Nadal and Novak Djokovic had to wait one more day for setting up their highly anticipated clash in the semifinals as their quarter-final matches were later cancelled due to rain.

China's Zheng Saisai and her Romanian partner Irina-Camelia Begu also saw their doubles quarter-finals put off until Wednesday.