Stadium: Court 1 Round: 25 Ground: Hardcourt indoor
| ITF Women Warsaw | 2017/06/22 14:00 | Kostova, Elitsa v Maja Chwalinska | 6-4,6-1 |
| ITF Women Saguenay | 2018/10/23 14:00 | Kostova, Elitsa v Jada Bui | 4-6,3-6 |
| WTA Luxembourg | 2018/10/14 11:50 | Kostova, Elitsa v Arantxa Rus | 2-6,3-6 |
| WTA Luxembourg | 2018/10/13 19:35 | Indy De Vroome v Kostova, Elitsa | 3-6,2-6 |
| Santa Margherita Di Pula, Simples W-WITF-ITA-27A | 2018/10/02 13:50 | Reka-Luca Jani v Kostova, Elitsa | 7-5,4-6,6-1 |
| Santa Margherita Di Pula, Simples W-WITF-ITA-27A | 2018/09/28 12:00 | Kostova, Elitsa v Samsonova, Liudmila | 3-6,4-6 |
| Santa Margherita Di Pula, Simples W-WITF-ITA-27A | 2018/09/27 12:00 | Kostova, Elitsa v Irene Burillo Escorihuela | 6-0,5-7,6-2 |
| Santa Margherita Di Pula, Simples W-WITF-ITA-27A | 2018/09/25 17:15 | Kostova, Elitsa v Jule Niemeier | 7-5,6-1 |
| ITF Women Saint Malo | 2018/09/18 10:20 | Kostova, Elitsa v Cagla Buyukakcay | 6-7,4-6 |
| ITF Women Saguenay | 2018/10/22 15:20 | Maja Chwalinska v Hogenkamp, Richel | 6-4,6-7,3-6 |
| ITF Women Valencia | 2018/09/24 09:00 | Andrea Gamiz v Maja Chwalinska | 6-2,6-2 |
| ITF Women Valencia | 2018/09/22 10:35 | Maria Andrienko v Maja Chwalinska | 0-6,1-6 |
| ITF Women Budapest | 2018/08/29 09:00 | Maja Chwalinska v Mrdeza, Tereza | 1-6,6-3,7-5 |
| ITF Women Budapest | 2018/08/28 12:10 | Maja Chwalinska v Dalma Galfi | 5-7,6-4,6-2 |
| ITF Women Budapest | 2018/08/27 10:00 | Kovacs, Zita v Maja Chwalinska | 1-6,2-6 |
| ITF Women Budapest | 2018/08/26 10:30 | Daniela Vismane v Maja Chwalinska | 4-6,6-4,2-6 |
| ITF Women Budapest | 2018/08/25 08:00 | Skamlova, Chantal v Maja Chwalinska | 2-6,2-6 |