Stadium: Court 1 Round: 54 Ground: Clay
| ITF M25 Koksijde | 2021/08/15 08:00 | Victor Ernaelsteen v Moritz Poswiat | 6-2,6-4 |
| ITF M15 Esch/Alzette | 2021/07/18 07:55 | Alexander Kotzen v Victor Ernaelsteen | 6-1,6-4 |
| ITF M15 Troisdorf | 2021/05/09 13:00 | Quin Verstegen v Victor Ernaelsteen | 0-6,5-7 |
| ITF M15 St Petersburg | 2021/04/12 07:00 | Timur Kiyamov v Victor Ernaelsteen | 6-2,6-2 |
| ITF M15 St Petersburg Qual | 2021/04/11 12:25 | Victor Ernaelsteen v Sergei Pogosian | 6-3,7-5 |
| ITF M15 Monastir | 2021/03/07 12:00 | Samuele Pieri v Victor Ernaelsteen | 6-4,6-3 |
| ITF M15 Monastir | 2021/02/28 08:00 | Noah Lopez v Victor Ernaelsteen | 7-6,6-2 |
| ITF M15 Cairo | 2020/12/06 10:30 | Abhinav Sanjeev Shanmugam v Victor Ernaelsteen | 6-2,6-3 |
| ITF M25 Wetzlar | 2021/08/03 15:30 | John Sperle v Osman Torski | 3-6,3-6 |
| UTR Pro Tennis Series Mulheim | 2021/07/30 13:30 | Hazem Naw v John Sperle | 6-4,6-2 |
| UTR Pro Tennis Series Mulheim | 2021/07/30 07:00 | Hendrik Jebens v John Sperle | 4-6,6-7 |
| UTR Pro Tennis Series Mulheim | 2021/07/29 08:30 | Marvin Schaber v John Sperle | 2-6,2-6 |
| UTR Pro Tennis Series Mulheim | 2021/07/28 12:00 | Tim Gennes v John Sperle | 1-6,3-6 |
| UTR Pro Tennis Series Mulheim | 2021/07/26 12:30 | Vasile Antonescu v John Sperle | 6-3,5-2 |
| ITF M15 Antalya | 2021/05/31 08:30 | Daniel Antonio Nunez v John Sperle | 6-4,7-5 |
| ITF M15 Antalya | 2021/05/23 07:00 | John Sperle v Jip Van Assendelft | 5-7,7-5,4-10 |