Eleven teenagers started the fortnight in the women's singles draw at the 2020 US Open, and as the third round gets underway on Friday, only four remain.
One of them is Marta Kostyuk of Ukraine, who's matched her best-ever Grand Slam result with a pair of victories this week, and will take on 2018 US Open champion Naomi Osaka in the first match inside Ashe.
Here's more on the 18-year-old upstart:
She first made a splash at 15.
Three years ago, Kostyuk, ranked world No. 571 at the time, burst onto the scene with a breakout performance at the Australian Open. Awarded a qualifying wild card to the 2018 Australian Open after winning the junior title a year prior, Kostyuk became the first player born in 2002 to play in a Grand Slam main draw thanks to three preliminary victories.
By defeating China's Peng Shuai in the first round, Kostyuk became the youngest player to win a main-draw match in Melbourne since Martina Hingis in 1996, and with a second-round victory over Aussie Olivia Rogowska, the Ukrainian became the youngest player to reach the third round of a Slam in over 20 years.
She's already bounced back from adversity in her young career.
The going has been anything but easy for Kostyuk since she announced herself on the international stage. Having started 2019 looking primed for the Top 100 and more at a career-high ranking of world No. 116, she'd dipped all the way down to world No. 320 following injury struggles and a loss of form by April.
Thanks to two runner-up finishes at ITF World Tennis Tour events in 2019, however, along with a maiden WTA tour-level quarterfinal appearance in Strasbourg, she bounced back to cut her ranking in half to a year-end No. 155.
She's part of a select group in 2020.
With professional tennis having been suspended for nearly six months in light of COVID-19, few players have a title on their ledger this season. Kostyuk has two.
In February, the teenager swept the singles and doubles titles at a $60,000 ITF World Tennis Tour event in Cairo, Egypt, with the former representing her first singles victory in two years. In the opening round of that event, she beat the No. 2 seed—Russia's Varvara Gracheva, who is having an Open to remember herself.
She was one of the last players in, and she's taken advantage.
Ranked world No. 137 entering the US Open, Kostyuk was not initially within the direct acceptances for this year's event. However, the teenager moved into the main draw at the 11th hour on Aug. 21, when former Top-10 player Andrea Petkovic withdrew.
She's making the most of her opportunity: Kostyuk's two victories this week over Russian Daria Kasatkina and No. 31 seed Anastasija Sevastova have each been notable on their own.
In the opening round, the 18-year-old needed just 59 minutes to beat the former Top-10 player, 6-1, 6-2, and she later earned a quality 6-3, 7-6 victory over the 2018 semifinalist—who had beaten another teen sensation, Coco Gauff, in Round 1.
She's making her US Open main-draw debut.
In fact, the 2020 US Open is just Kostyuk's second-ever appearance in a main draw at a major. After that maiden Australian Open showing, she fell in the qualifying rounds in six other Grand Slams.
When she faces Osaka on Friday afternoon, Kostyuk will bid for a maiden victory against a Top-10 player in her third-ever match against a player in that ranking range.
