The 15-year-old was rewarded with an all-Ukrainian clash against fourth seed Elina Svitolina as her fairytale run at the year’s first Grand Slam continued with a win over local wildcard Olivia Rogowska 6-3, 7-5.
It had commentators gushing that Kostyuk was “the future of tennis” as she extended her win streak at Melbourne Park to an incredible 11 matches after lifting the Australian Open girls’ title in 2017 and coming through qualifying this year.
“This is the future, ladies and gentlemen. Fifteen years of age,” said former British number one Sam Smith on Australia’s Channel 7. “This is an incredible story. This is the future of tennis on your screen.”
Before the start of this week Kostyuk’s total career prize money was $6,733, but she already has plans for the bumper $142,500 pay day she will earn even if she loses to Svitolina in the third round.
“Maybe I will get presents for my family, first of all, of course, because I have big family,” she said. “And then for myself a bit. Yeah.”
Playing since the age of five and watched by tennis-playing mum and coach Talina Beyko, who once reached 391st in the world, in her player’s box on Margaret Court Arena, Kostyuk said she had been used to setting new standards.
“I think I broke some records every year so I feel OK about it,” she said.
In the first round she had dismantled Chinese number one and 25th seed Peng Shuai in straight sets in just 57 minutes.
The talented Kostyuk continued in the same vein against Rogowska, taking the first set in 39 minutes.
“I didn’t feel like she was 15 at all,” said Rogowska. “I feel she’s going to be a dangerous player when she grows up. Obviously she had some silly errors, I think with experience she’ll clean that up.”
Svitolina clearly knows what to expect when she faces her young compatriot on Friday.
“I little bit watched her first round,” said the world number four after coming through a three-set battle against Katerina Siniakova.
“You know, she has nothing to lose, she goes just for everything. You know, a little bit like a headless chicken.”
The youngster is managed by former player Ivan Ljubicic, Roger Federer’s coach, and said she was pleased to have such experience in her corner.
“He is always helping me, telling me what was wrong, even when I win,” she said laughing. “I am lucky to have his experience.”
And long hours of practice, she said, was the key to her success.
“Well, I heard a lot of times that I’m talented, and I know that,” she told reporters with all the swagger of confident youth.
“But I know that only talent will not help me to play good. So I can say that I’m working pretty hard.”