The first Latvian woman to reach a Grand Slam semifinal in the professional era, Ostapenko credits her strong footwork to a hobby, ballroom dancing (she prefers the samba).
"When she said that I was known for that sort of thing on the circuit, really?"
Bacsinszky, Ostapenko's opponent, will be making her second career Grand Slam semifinal appearance (she lost to Serena Williams in the 2015 French Open semifinals).
But that would be to discount the threat of Latvia's fearless youngster Jelena Ostapenko and Swiss 30th seed Timea Bacsinszky who are first on Court Philippe Chatrier.
Ostapenko is not looking beyond her clash with Bacsinszky as she revels in an unexpected challenge for the Coupe Suzanne Lenglen.
"Of course I think it helped me. We had a hurricane, a sandstorm, and we nearly had snow, too", Bacsinszky told the crowd at Court Philippe Chatrier. "It was really tough to keep my concentration, but I'm really happy and proud". Maybe it came very early, or maybe not, but I think she worked to be in the semi-finals - she didn't have any retirements, she was one set down against some opponents, she fought hard to be in the semi-finals every match, so I think she deserves this.
Wicked winds bent the flag poles and red brick dust was whipped up into the players' eyes in the opening games in which Ostapenko could hardly locate the court. They play Thursday, which happens to be Ostapenko's 20th birthday and Bacsinszky's 28th.
Mixed in with her scintillating winners, including forehands faster than anything men's world number one Andy Murray has managed here so far, were 45 unforced errors, some of which could have been included in a video nasty.
The pair held serve to open the second set and, with Mladenovic facing a break point in the third game, the players were called off court after the dark grey clouds finally broke and heavy rain swept the stadium. I was happy for her that she was in the semi-final, as well-and that we are sharing the same birthday.
Romanian Simona Halep has shown the full extent of her defensive skills to beat Karolina Pliskova 6-4 3-6 6-3 and reach her second French Open final.
"She served pretty well, and then I just got my game back (so afterwards) I felt quite confident. It was really tough but I think I found my game".
She said: "The magic has been happening for me here always - even the first time I came here as a little kid".