Paris, Jun 7 (IANS): Switzerland's Timea Bacsinszky and Latvia's Jelena Ostapenko advanced to the women's singles semi-finals in the French Open tennis championships.

The 27-year-old Bacsinszky on Tuesday defeated Frenchwoman Kristina Mladenovic 6-4, 6-4 in one hour and 49 minutes in a quarter final match, reports Efe.

In the other match, teenager Ostapenko, playing at Roland Garros for just the second time in her career, defeated former world No.1 Denmark's Caroline Wozniackion 4-6, 6-2, 6-2 in one hour and 53 minutes.

"It was really difficult because we had all the seasons rolled into one today," Bacsinszky said. "We had a sand storm, a hurricane and we almost had snow too. It was really tough to keep my concentration all day long."

The Swiss world No. 31 also had to contend with a crowd that constantly tried to help the 24-year-old Mladenovic, the world No.14, stay in the match.

"I'm really happy and proud. For many years, big things have happened for me at Roland Garros. I'm really happy to be through to my second semi-final here. I feel really privileged," Bacsinszky said.

Bacsinszky made the last four in Paris in 2015, losing to eventual champion Serena Williams of the US.

"I'm really happy, I can't believe it," the 19-year-old Ostapenko said.

The Latvian teenager, ranked 47th in the world, did not wilt after dropping the first set to the 26-year-old Wozniacki, the world No. 12, who has played in two Grand Slam finals.

"It was tough because we had to go away two times from the court," Ostapenko said, referring to the rain delays.

The Latvian is the first teenager to reach the French Open semi-finals since 2007 when Serbia's Ana Ivanovic pulled off the feat. Ivanovic won the title at the French Open the next year.

"Caroline is a tough opponent, I knew I had to stay aggressive, I lost it sometimes, but I found my game," Ostapenko said.