PARIS — Mirra Andreeva is heading to the French Open final.On a breezy, cool day in Paris, the 19-year-old Russian took advantage of a tight and nervous version of Marta Kostyuk, the 23-year-old from Ukraine who had not lost a match in more than two months.Andreeva did what quality players do when they see an opponent decomposing 80 feet away. She kept her foot on the gas, kept the ball in the court and cruised to a 6-1, 6-3 win in just shy of 80 minutes.For nearly five weeks of the clay-court season, Kostyuk appeared to have finally blossomed into the the fully-formed star she seemed destined to become when she started winning matches on the WTA Tour eight years ago.She had a command of the ball and her emotions in a way she had never had before. As her country, Ukraine, continues to be attacked by Russian forces, she has spoken about the meaning of her victories, her hopes for her country and the tennis dreams she was finally fulfilling. Kostyuk, no matter the result in Paris Thursday, had grown up.On Thursday though, the teenage Andreeva was the adult on the court, at least in pure tennis terms. She sloughed off some early nerves, finding the level she needed and the groove she wanted to stay in to make it to her first Grand Slam final, a little more than three years after her breakout, when she was just 15.