Stadium: Court 4 Round: 25 Ground: Clay
| ITF M15 L'Aquila | 2021/07/15 07:00 | Luciano Darderi v Prechtel, Sebastian | 6-7,6-3,6-2 |
| ITF M15 L'Aquila | 2021/07/14 08:00 | Prechtel, Sebastian v Procopio, Alessandro | 6-2,6-4 |
| ITF M25 Velenje | 2021/07/08 08:00 | Prechtel, Sebastian v Gonzalo Lama | 4-6,1-6 |
| ITF M25 Velenje | 2021/07/07 10:45 | Prechtel, Sebastian v Malesevic, Nemanja | 6-3,6-3 |
| Sarajevo, Singles Main, M-ITF-BIH-05A | 2021/06/02 09:00 | Kekez, Duje v Prechtel, Sebastian | 6-1,6-1 |
| ITF - M25 Kiseljak | 2021/05/27 12:00 | Zsombor Piros v Prechtel, Sebastian | 6-3,6-4 |
| ITF - M25 Kiseljak | 2021/05/25 13:05 | Prechtel, Sebastian v Kekez, Duje | 3-6,6-3,6-4 |
| Sibenik, Singles M-ITF-CRO-05A | 2021/05/20 08:00 | Zsombor Piros v Prechtel, Sebastian | 6-1,6-1 |
| ITF M15 Esch/Alzette | 2021/07/20 13:00 | von Der Schulenburg, Jeffrey v Guy Den Ouden | 6-4,3-6,7-5 |
| Challenger Amersfoort | 2021/07/11 14:00 | Guy Den Ouden v Hidalgo, Diego | 3-6,6-7 |
| ITF M25 Marburg | 2021/07/05 12:05 | Sabanin, Yan v Guy Den Ouden | 7-6,6-4 |
| ITF M25 The Hague | 2021/06/28 10:15 | Guy Den Ouden v Henri Squire | 2-6,0-6 |
| ITF M25 Alkmaar | 2021/06/23 10:35 | Deney Wassermann v Guy Den Ouden | 7-6,7-5 |
| ITF - M15 Sharm El Sheikh | 2020/11/19 10:10 | Guy Den Ouden v Miljan Zekic | 6-7,6-7 |
| ITF - M15 Sharm El Sheikh | 2020/11/18 12:45 | Juan Bautista Otegui v Guy Den Ouden | 6-1,3-6,4-6 |
| ITF - M15 Sharm El Sheikh | 2020/11/11 08:00 | Guy Den Ouden v von Der Schulenburg, Jeffrey | 2-6,5-7 |