Stadium: Court central Round: 25 Ground: Clay
| US Open Women | 2018/08/29 23:05 | Williams, Serena v Witthoeft, Carina | 6-2,6-2 |
| US Open Women | 2018/08/27 23:40 | Caroline Dolehide v Witthoeft, Carina | 3-6,6-7 |
| New Haven, USA | 2018/08/18 19:15 | Parmentier, Pauline v Witthoeft, Carina | 7-5,6-2 |
| WTA Gstaad | 2018/07/17 08:30 | Rodina, Evgeniya v Witthoeft, Carina | 6-7,6-4,7-6 |
| ITF Women Versmold | 2018/07/13 15:35 | Witthoeft, Carina v Laura Siegemund | 1-6,3-6 |
| ITF Women Versmold | 2018/07/12 12:40 | Witthoeft, Carina v Soler-Espinosa, Silvia | 3-6,7-5,7-5 |
| ITF Women Versmold | 2018/07/11 17:15 | Witthoeft, Carina v Ulrikke Eikeri | 6-3,4-6,6-3 |
| Wimbledon Women | 2018/07/03 17:30 | Suarez Navarro, Carla v Witthoeft, Carina | 6-2,6-4 |
| ITF Women Zagreb | 2018/09/06 16:50 | Kostova, Elitsa v Tena Lukas | 6-1,2-6,3-6 |
| ITF Women Zagreb | 2018/09/05 16:15 | Kostova, Elitsa v Bukta, Agnes | 6-3,6-4 |
| ITF Women Budapest | 2018/08/28 09:00 | Raluca Georgiana Serban v Kostova, Elitsa | 6-2,7-5 |
| US Open Women | 2018/08/21 16:15 | Kostova, Elitsa v Fiona Ferro | 1-6,7-5,4-6 |
| Prague, Singles W-WITF-CZE-06A | 2018/07/27 10:40 | Kostova, Elitsa v Hogenkamp, Richel | 6-7,7-6,2-6 |
| Prague, Singles W-WITF-CZE-06A | 2018/07/26 13:10 | Kostova, Elitsa v Lucrezia Stefanini | 6-2,6-4 |
| Prague, Singles W-WITF-CZE-06A | 2018/07/25 09:30 | Kostova, Elitsa v Katarina Zavatska | 6-2,4-6,6-4 |
| WTA Gstaad | 2018/07/18 10:30 | Marketa Vondrousova v Kostova, Elitsa | 6-4,6-4 |