Marta Kostyuk arrived as a teenage headline act and spent years making good on it. The Kyiv-born right-hander made her major main-draw debut at the 2018 Australian Open as a wildcard qualifier — beating Barbora Krejčíková en route — to become the first player born in 2002 to play a Grand Slam main draw, and the youngest to qualify for a major since Sesil Karatantcheva in 2005. By reaching the third round in Melbourne she became the youngest player to do so at a major since Mirjana Lučić-Baroni at the 1997 US Open. She'd already won the junior title there in 2017, but the senior payoff took years of ITF grind.
The game is built on early, flat ball-striking and a refusal to give the baseline back. She plays an aggressive, intense style, thriving on taking the ball early — particularly off the backhand side and on return, where her timing lets her impose immediate pressure. She's also one of the tour's most outspoken figures — a vocal advocate for Ukraine who has never softened that line.
The breakthrough came in 2026. After winning the WTA 250 in Rouen, Kostyuk moved to No. 23 ahead of Madrid, then collected her maiden WTA 1000 title at the Madrid Open by beating Mirra Andreeva 6-3, 7-5 in the final. She entered as the No. 26 seed and got past the likes of Jessica Pegula, Linda Noskova and Andreeva. That lifted her to a career-high No. 15 on 4 May 2026, the first WTA 1000 title among her three tour singles trophies.
Madrid was a launchpad, not a ceiling. At the French Open, she reached her maiden major semifinal — beating Iga Świątek in the fourth round and Elina Svitolina in the first all-Ukrainian Grand Slam quarterfinal of the Open Era — becoming the first Ukrainian woman to reach the Roland-Garros semifinals. Andreeva ended her 17-match winning streak in the last four.