Week 40 WTA pick
Right-handed, currently No. 139 in the WTA singles rankings.
Career-High Rank
No. 139
SINGLES
Current Rank
No. 139
28 SEP 2026
Age
19
B. 28 JUN 2007
RTT Pick
Wk 40
RISING STAR
Subscriber exclusive · Issue No. 14
Serbia makes champions, then sends them away
A Novi Sad club at five, then IMG in Florida, like the Serbian stars before her. European U18 champion, then No. 898 to No. 190 in a single pro season. Nine pages on the junior record, the team and the plateau before September 2026.
Country
🇷🇸 Serbia
Tour
WTA singles
Plays
Right-handed
Age
19
Born
28 June 2007
Current Rank
No. 139
Career High
No. 139
Career W–L
97–50
2026 W–L
36–24
Kostovic arrived on the pro tour with one of the stronger junior records of her generation. She reached a career-high No. 6 in the ITF junior rankings, made the quarterfinals of junior Wimbledon in 2024 and 2025 and of the junior US Open in 2024, and reached the third round at Roland Garros twice. She is coached by Aleksandar Vlaović. Her first big pro title came in August 2025 at a W75 on the Serbian Tennis Tour, where she beat Lina Gjorcheska 7–5, 6–3 in the final.
2026 has been the step up. She played qualifying at the Australian Open and Roland Garros, then won the Amstetten W100 in July, beating Vivian Wolff 6–4, 6–0 in the final. At Wimbledon she got the draw she had asked for, Aryna Sabalenka in the first round. She was ranked No. 186 on 14 September. That week she reached her first tour-level quarterfinal at the São Paulo WTA 250, where she lost to former RTT pick Kaitlin Quevedo.
Seeded fifth at the Ankara WTA 125 (21–27 September), she reached the final without dropping a set. Her wins included Tian 6–0, 7–5 and Iatcenko 7–5, 7–5. She took the first set of the final 6–2 before Berfu Cengiz came back to win 2–6, 6–4, 7–5. The run moved her 20 places in the 28 September release to a career-high No. 139, up 47 places in a fortnight. She is 36–24 on the season.
"I'm a big fighter. Yes, I fight for every point."— wtatennis.com, 26 June 2026
"I've never lost here. I feel like this is my court."
ON ROEHAMPTON, BEFORE WIMBLEDON · WTATENNIS.COM"I'm a big fighter. Yes, I fight for every point."
BEFORE FACING SABALENKA · WTATENNIS.COM