Stadium: Court 3 Round: 25 Ground: Clay
| ITF M25 Alkmaar | 2021/06/21 18:00 | Vladimir Ivanov v Guy Den Heijer | 3-6,6-7 |
| ITF M15 Parnu | 2021/08/07 09:00 | Mattias Siimar v Vladimir Ivanov | 6-4,3-6,6-2 |
| ITF M15 Parnu | 2021/08/06 08:00 | Vladimir Ivanov v Otto Virtanen | 2-6,6-4,7-6 |
| ITF M15 Parnu | 2021/08/05 07:00 | Vladimir Ivanov v Siim Troost | 4-6,7-6,6-3 |
| ITF M15 Parnu | 2021/08/04 09:20 | Vladimir Ivanov v Milan Welte | 7-5,1-6,6-3 |
| ITF M25 The Hague | 2021/06/29 11:20 | Lucas Gerch v Vladimir Ivanov | 6-1,6-2 |
| ITF M25 The Hague | 2021/06/28 08:00 | Vladimir Ivanov v Raphael Collignon | 6-2,6-2 |
| ITF M25 The Hague | 2021/06/27 08:00 | Vladimir Ivanov v Patrick Zahraj | 4-6,6-3,10-6 |
| ITF M25 Alkmaar | 2021/06/21 18:00 | Vladimir Ivanov v Guy Den Heijer | 3-6,6-7 |
| ITF M15 Oldenzaal | 2021/08/17 09:15 | Guy Den Heijer v Alexis Canter | 6-4,6-4 |
| ITF M15 Oldenzaal | 2021/08/16 10:00 | Guy Den Heijer v Noel Larwig | 6-3,6-4 |
| ITF M15 Oldenzaal | 2021/08/15 14:00 | Guy Den Heijer v Paulo Knippling | 6-3,6-4 |
| UTR Pro Tennis Series Mulheim | 2021/07/30 13:30 | Guy Den Heijer v Alexander Hoogmartens | 6-2,3-6,4-6 |
| UTR Pro Tennis Series Mulheim | 2021/07/29 13:30 | Mark Wallner v Guy Den Heijer | 2-6,3-6 |
| UTR Pro Tennis Series Mulheim | 2021/07/29 07:00 | Matthew Thomson v Guy Den Heijer | 1-6,3-6 |
| UTR Pro Tennis Series Mulheim | 2021/07/27 09:30 | Billy Harris v Guy Den Heijer | 3-6,2-6 |
| UTR Pro Tennis Series Mulheim | 2021/07/26 11:00 | Guy Den Heijer v Tim Sandkaulen | 7-5,6-3 |