Stadium: Center (M15) Round: 25 Ground: Clay
| ITF M15 Kazan | 2021/03/09 12:15 | Sergey Fomin v Denis Klok | 6-2,6-4 |
| ITF M15 Antalya | 2021/02/07 06:00 | Benedikt Henning v Denis Klok | 6-1,6-1 |
| ITF M25 Villena | 2021/02/01 10:30 | Denis Klok v Alejandro Manzanera Pertusa | 2-6,2-6 |
| ITF M25 Villena | 2021/01/31 10:30 | Denis Klok v Mario Mansilla Diez | 6-2,6-3 |
| ITF M15 Manacor | 2021/01/05 14:00 | Denis Klok v Alberto Barroso Campos | 1-6,3-6 |
| ITF M15 Manacor | 2021/01/04 11:30 | Denis Klok v Peter Benjamin Privara | 6-0,5-7,15-13 |
| ITF M15 Antalya | 2020/03/12 07:55 | Sergi Perez Contri v Denis Klok | 6-4,6-2 |
| ITF M15 Antalya | 2020/03/11 07:00 | Rigele Te v Denis Klok | 3-6,1-6 |
| ITF M15 Nur-Sultan | 2021/02/08 04:00 | Islam Orynbasar v Iiro Vasa | 3-6,2-6 |
| ITF M15 Nur-Sultan | 2021/02/01 07:30 | Dominik Palan v Islam Orynbasar | 7-6,6-2 |