| ITF Women Macon | 10/24 16:55 | 25 | [209] Elitsa Kostova v Jamie Loeb [144] | 2-6,2-6 | |
| ITF Women Obidos | 10/11 11:30 | 25 | [454] Berfu Cengiz v Elitsa Kostova [205] | 3-6,6-3,6-2 | |
| ITF Women Templeton | 09/29 20:40 | 27 | [163] Jamie Loeb v Elitsa Kostova [215] | 6-2,6-4 | |
| ITF Women Templeton | 09/28 19:45 | 26 | Elitsa Kostova v Alisa Kleybanova | 6-4,3-6,6-2 | |
| ITF Women Templeton | 09/27 22:00 | 25 | [215] Elitsa Kostova v Sabrina Santamaria [454] | 6-1,6-3 | |
| ITF Women Tampico | 09/19 21:25 | 25 | [211] Elitsa Kostova v Victoria Rodriguez [255] | 6-7,2-6 | |
| ITF Women Las Vegas | 09/17 20:05 | 29 | [224] Sesil Karatantcheva v Elitsa Kostova [258] | 6-4,4-6,7-5 | |
| ITF Women Las Vegas | 09/16 21:30 | 28 | Anna Karolina Schmiedlova v Elitsa Kostova | 5-7,4-6 | |
| ITF Women Las Vegas | 09/15 17:00 | 27 | Elitsa Kostova v Maria Mateas | 4-6,6-2,7-6 | |
| ITF Women Las Vegas | 09/14 19:00 | 26 | [258] Elitsa Kostova v Chieh-Yu Hsu [374] | 6-3,6-1 | |
| ITF Women Las Vegas | 09/12 20:10 | 25 | [258] Elitsa Kostova v An-Sophie Mestach [323] | 6-2,6-2 | |
| ITF Women Mamaia | 08/30 07:00 | 25 | [350] Dea Herdzelas v Elitsa Kostova [231] | 6-4,6-4 | |
| ITF Women Artvin | 08/24 06:30 | 26 | [236] Elitsa Kostova v Vitalia Diatchenko [282] | 3-6,3-6 | |
| ITF Women Artvin | 08/22 06:30 | 25 | [236] Elitsa Kostova v Valeriya Strakhova [333] | 4-6,6-3,6-0 | |
| ITF Women Montreux | 08/19 10:00 | 27 | Elitsa Kostova v Deborah Chiesa | 4-6,5-7 | |
| ITF Women Montreux | 08/17 09:20 | 26 | [247] Elitsa Kostova v Priscilla Heise [434] | 3-6,7-6,6-0 | |
| ITF Women Montreux | 08/15 08:00 | 25 | Elitsa Kostova v Fiona Ganz | 6-3,4-6,6-4 | |
| ITF Women Chiswick | 08/10 09:30 | 27 | [354] Vitalia Diatchenko v Elitsa Kostova [244] | 6-3,6-2 | |
| ITF Women Chiswick | 08/09 12:45 | 26 | [307] Paula Badosa Gibert v Elitsa Kostova [244] | Retired | |
| ITF Women Chiswick | 08/08 09:30 | 25 | [302] Harriet Dart v Elitsa Kostova [244] | 6-7,6-3,1-6 | |
| ITF Women Prague | 07/26 10:40 | 25 | [223] Petra Krejsova v Elitsa Kostova [246] | 4-6,7-6,6-0 | |
| WTA Gstaad | 07/18 10:05 | 25 | [20] Caroline Garcia v Elitsa Kostova [220] | 7-5,6-1 | |
| ITF Women Contrexeville | 07/11 09:40 | 25 | [211] Irina Maria Bara v Elitsa Kostova [151] | 6-4,6-0 | |
| Wimbledon Women Qual | 06/29 10:00 | 45 | [246] Irina Falconi v Elitsa Kostova [151] | 6-3,6-3 | |
| Wimbledon Women Qual | 06/27 10:00 | 44 | [151] Elitsa Kostova v Fangzhou Liu [133] | 6-4,6-1 | |
| ITF Women Warsaw | 06/24 10:20 | 27 | [153] Elitsa Kostova v Sesil Karatantcheva [251] | 7-5,2-6,4-6 | |
| ITF Women Warsaw | 06/22 14:00 | 26 | Elitsa Kostova v Maja Chwalinska | 6-4,6-1 | |
| ITF Women Warsaw | 06/21 12:50 | 25 | Elitsa Kostova v Diana Sumova | 6-2,6-2 | |
| ITF Women Hodmezovasarhely | 06/15 11:20 | 26 | Elitsa Kostova v Alexandra Ignatik | 2-6,2-6 | |
| ITF Women Hodmezovasarhely | 06/15 10:30 | - | [153] Elitsa Kostova v Alexandra Cadantu [172] | 2-6,2-5 |