Stadium: Court 3 Round: 44 Ground: Clay
| ITF M25 Koksijde | 2021/08/16 08:00 | Ernaelsteen, Victor v John Sperle | 3-6,3-6 |
| ITF M25 Koksijde | 2021/08/15 08:00 | Ernaelsteen, Victor v Poswiat, Moritz | 6-2,6-4 |
| ITF M15 Esch/Alzette | 2021/07/18 07:55 | Kotzen, Alexander v Ernaelsteen, Victor | 6-1,6-4 |
| ITF M15 Troisdorf | 2021/05/09 13:00 | Verstegen, Quin v Ernaelsteen, Victor | 0-6,5-7 |
| ITF M15 St Petersburg | 2021/04/12 07:00 | Kiyamov, Timur v Ernaelsteen, Victor | 6-2,6-2 |
| ITF M15 St Petersburg Qual | 2021/04/11 12:25 | Ernaelsteen, Victor v Sergei Pogosian | 6-3,7-5 |
| ITF - M15 Monastir | 2021/03/07 12:00 | Samuele Pieri v Ernaelsteen, Victor | 6-4,6-3 |
| ITF - M15 Monastir | 2021/02/28 08:00 | Noah Lopez v Ernaelsteen, Victor | 7-6,6-2 |
| ITF M15 Frederiksberg | 2021/08/02 12:00 | Leonardo Catani v Slavic, Nikola | 2-6,2-6 |
| ITF M15 Frederiksberg | 2021/08/01 10:00 | Leonardo Catani v Sudzum, Marcel Marlon | 7-6,6-2 |
| ITF M15 Vejle | 2021/07/27 17:20 | Leonardo Catani v Korsgaard, Henrik Heise | 3-6,3-6 |
| ITF M15 Vejle | 2021/07/26 14:40 | Yannik Steinegger v Leonardo Catani | 5-7,6-2,10-4 |
| ITF M15 Vejle | 2021/07/25 11:00 | Schiavetti, Pietro v Leonardo Catani | 2-6,0-6 |
| ITF M15 Perugia | 2021/07/18 11:30 | Leonardo Catani v Bertuccioli, Federico | 4-6,2-6 |
| ITF M15 Gaiba | 2021/06/07 09:30 | de Cuyper, Julien v Leonardo Catani | 6-3,6-3 |
| ITF M15 Cairo | 2021/05/04 07:55 | Kawakami, Rimpei v Leonardo Catani | 7-5,6-0 |