Stadium: Court 3 Round: 54 Ground: Clay
| ITF Women Tucepi | 2018/04/22 08:00 | Алиса Гиллан v Pavkovic, Marina | 6-4,6-4 |
| ITF Women Tucepi | 2018/04/21 09:30 | Леа Юркович v Pavkovic, Marina | 0-6,0-6 |
| ITF Women Szekesfehervar | 2018/09/02 08:00 | Malatinska, Justyna v Kostic, Katarina | 6-2,3-6,6-4 |
| ITF Women Vrnjacka Banja | 2018/08/19 10:00 | Kostic, Katarina v Ника Зупанчич | 3-6,6-4,2-6 |
| Prokuplje, Singles W-WITF-SRB-02A | 2018/07/12 08:40 | Kostic, Katarina v Барбара Бонич | 0-6,4-6 |
| Prokuplje, Singles W-WITF-SRB-02A | 2018/07/11 09:00 | Киара Цветкович v Kostic, Katarina | 2-6,6-2,2-6 |
| ITF Women Prokuplje Qual | 2018/07/09 07:00 | Костанца Траверси v Kostic, Katarina | 4-6,3-6 |
| ITF Women Prokuplje Qual | 2018/06/30 07:00 | Kostic, Katarina v Андриана Стойлкович | 2-6,2-6 |
| ITF Women Maribor | 2018/06/13 08:00 | Нина Алибалик v Kostic, Katarina | 7-5,6-3 |
| ITF Women Maribor Qual | 2018/06/11 08:40 | Kostic, Katarina v Morton, Emily | 6-2,6-2 |