She does not feel invincible nor does she think about her 17-match winning streak. She is just delighted and excited to be in the last four. And, anyway, what Mirra Andreeva is feeling at the moment is none of her concern.

Kostyuk is the fifth player this century to win the first 17 matches of her clay-court season, the others being Venus Williams, Serena Wiliams, Justine Henin and Iga Swiatek. And they all did pretty well in Paris. She is in good company, then. But what has been is gone; it is what is to come that matters. That is where her coach, Sandra Zaniewska, comes into play.

The two have been working together for three years and Kostyuk cannot praise her mentor highly enough. They laugh together, they enjoy each other’s company and they have developed a winning formula. Only once in the past 12 days has there been a harsh look from Zaniewska but it was for a reason. And it worked.

In the third set of the quarter-final against Elina Svitolina, she missed a shot she should have made. Zaniewska glared at her from the stands. “I don't think she was really pissed, but she was really intense,” Kostyuk said. “And she showed me what I had to do, which was I had to hit the ball that I didn't hit. I don't think Sandra is often like this, but it was a very clear sign on what I had to do, and I listened to it.”

Kostyuk never looked back and now Zaniewska will attempt to work her magic again to get her charge to the final.

“I think Sandra deserves it all because she really gave her soul for this work with me,” Kostyuk said. “She changed me so much as a person.

I think we both changed; we've both grown together in this working relationship. For sure, I definitely wouldn't be here without her.” 

A good starting point for the pre-match pep talk would be the fact that Kostyuk has played Andreeva twice this year and won in straight sets on each occasion, the last time being in the Madrid final. Yet there is more riding on this match than just personal success: Kostyuk is playing for the people of Ukraine. If news of her wins brings a little hope or relief to the people back home, then it has been a good day.

That said, playing Andreeva is not part of that equation. There is no extra edge to Thursday's encounter because of the war in Ukraine. Kostyuk is here to play tennis, plain and simple.

“I don't think if I didn't separate it, I would be able to beat Mirra two times that I played her this year,” she said. “For sure I got much better at it right now. I usually never care who is on the other side of the net. I'm there to play tennis and do my job, and that's it.”

Andreeva is of much the same opinion. She is here to reach her first Grand Slam final; she is thinking about the ball that is coming towards her, not the woman who is hitting it.

“It doesn't matter who I play,” she said. “I really try to play against the ball that is coming at me. Usually it doesn't matter to me who I'm playing against, so I'm trying to really focus on the game and on the game plan that I have to use on the court.”

She is also trying to not to put too much pressure on herself. Andreeva believes that everything happens for a reason so if she wins, it was meant to be and if she doesn’t, then that was meant to be, too.

“I think that I'm just going to try to keep using the same mindset of giving my best,” she said. “Giving my 100 per cent no matter what happens. I feel like it's just easier for me to play when I have this mindset on.

“I'm just going to try to do everything I can on the court, fight, and we'll see. The better player will win.”