Stadium: Court 4 Round: 25 Ground: Clay
| ITF M15 - Oldenzaal | 2021/08/17 07:30 | Mattia Bellucci v Karlo Cubelic | 7-6,7-5 |
| ITF - M15 - Monastir | 2021/08/08 07:30 | Luca Potenza v Mattia Bellucci | 3-6,3-6 |
| ITF - M15 - Monastir | 2021/08/07 07:30 | Daniil Glinka v Mattia Bellucci | 4-6,3-6 |
| ITF - M15 - Monastir | 2021/08/06 07:30 | Thomas Fancutt v Mattia Bellucci | 3-6,4-6 |
| ITF - M15 - Monastir | 2021/08/05 08:50 | Mattia Bellucci v Khololwam Montsi | 6-2,6-2 |
| ITF - M15 - Monastir | 2021/08/04 17:25 | Mattia Bellucci v Jacob Brumm | 6-1,6-3 |
| ITF - M15 - Monastir | 2021/07/27 14:00 | Erik Crepaldi v Mattia Bellucci | 7-6,6-1 |
| ITF - M15 - Monastir | 2021/07/24 08:30 | Mattia Bellucci v Matias Franco Descotte | 0-6,2-6 |
| ITF M15 - Frederiksberg | 2021/08/03 10:55 | Guy Den Ouden v Sandro Kopp | 4-6,4-6 |
| ITF M15 - Vejle | 2021/07/30 14:30 | Jonathan Mridha v Guy Den Ouden | 6-3,6-4 |
| ITF M15 - Vejle | 2021/07/29 16:30 | Guy Den Ouden v Mick Veldheer | 6-4,6-0 |
| ITF M15 - Vejle | 2021/07/28 11:50 | Sebastian Prechtel v Guy Den Ouden | 2-6,2-6 |
| ITF M15 - Esch/Alzette | 2021/07/20 13:00 | Jeffrey Von Der Schulenburg v Guy Den Ouden | 6-4,3-6,7-5 |
| Challenger Amersfoort | 2021/07/11 14:00 | Guy Den Ouden v Diego Hidalgo | 3-6,6-7 |
| ITF M25 - Marburg | 2021/07/05 12:05 | Yan Sabanin v Guy Den Ouden | 7-6,6-4 |
| ITF M25 - Haag | 2021/06/28 10:15 | Guy Den Ouden v Henri Squire | 2-6,0-6 |