France: W60 Biarritz - Doubles - Main |
| Quarter-finals | Cascino E./Kostova E. | Selekhmeteva O./Vismane D. | 1:2 (4:6, 6:4, 4:10) | dettagli | 14.07.2021 |
France: W100 Contrexeville - Doubles - Main |
| Quarter-finals | Hesse A./Seguel D. | Fetecau I./Kostova E. | WO. | dettagli | 08.07.2021 |
| 1/8-finals | Kempen M./Zuger J. | Fetecau I./Kostova E. | WO. | dettagli | 07.07.2021 |
United Arab Emirates: W25 Dubai - Doubles - Main |
| Quarter-finals | Grey S. B./Kostova E. | Choi J. H./Han N. | 0:2 (1:6, 1:6) | dettagli | 01.04.2021 |
| 1/8-finals | Raina A./Savinykh V. | Grey S. B./Kostova E. | 1:2 (6:4, 4:6, 10:12) | dettagli | 31.03.2021 |
Spain: W25 Las Palmas de Gran Canaria - Doubles - Main |
| Quarter-finals | Lazaro Garcia A./Papamichail D. | Hesse A./Kostova E. | 2:0 (6:2, 7:5) | dettagli | 19.11.2020 |
| 1/8-finals | Hesse A./Kostova E. | Berlanga Bandera M./Lerby C. | 2:0 (6:1, 6:2) | dettagli | 17.11.2020 |
France: W60+H Saint-Malo - Doubles - Main |
| Semi-finals | Kania-Chodun P./Piter K. | Kostova E./Lepchenko V. | 2:0 (6:1, 7:5) | dettagli | 11.09.2020 |
| Quarter-finals | Bara I./Guerrero Alvarez E. | Kostova E./Lepchenko V. | 0:2 (3:6, 5:7) | dettagli | 10.09.2020 |
| 1/8-finals | Kostova E./Lepchenko V. | Jacquemot E./Yashina E. | 2:0 (6:0, 6:3) | dettagli | 09.09.2020 |
Egypt: W25 Cairo - Doubles - Main |
| 1/8-finals | Lee P.-C./Lee Y.-H. | Kostova E./Kubareva A. | 2:0 (6:3, 6:3) | dettagli | 10.03.2020 |
Slovakia: W25 Trnava 2 - Doubles - Main |
| Quarter-finals | Juhaszova V./Kostova E. | Bondar A./Mihalikova T. | 0:2 (3:6, 64:7) | dettagli | 13.02.2020 |
| 1/8-finals | Juhaszova V./Kostova E. | Berankova K./Yashina E. | 2:0 (7:63, 6:3) | dettagli | 11.02.2020 |
Slovakia: W25 Trnava - Doubles - Main |
| 1/8-finals | Juhaszova V./Kostova E. | In-Albon Y./Perrin C. | 0:2 (5:7, 4:6) | dettagli | 04.02.2020 |