Stadium: Court 4 Round: 44 Ground: Clay
| ITF M25 Poznan | 2021/08/22 08:00 | Weightman, Oscar v Ivan Kazakov | 6-3,2-6,1-10 |
| ITF M15 Warmbad-Villach | 2021/08/16 07:00 | Ivan Kazakov v Achondo, Gonzalo | 6-3,0-6,8-10 |
| ITF - M15 Antalya | 2021/06/27 06:30 | Ivan Kazakov v Stefanos Sakellaridis | 1-6,4-6 |
| ITF - M15 Antalya | 2021/06/20 07:00 | Ivan Kazakov v Ray Ho | 2-6,1-6 |
| ITF - M15 Tbilisi | 2021/05/18 05:30 | Aleksandr Braynin v Ivan Kazakov | 6-2,6-2 |
| ITF - M15 Tbilisi | 2021/05/17 05:30 | Ivan Kazakov v Nashatyrkin, Roman | 6-1,6-1 |
| ITF - M15 Tbilisi | 2021/05/16 06:00 | Baklanov, Egor v Ivan Kazakov | 6-7,6-3,1-10 |
| ITF - M15 Antalya | 2021/04/18 07:00 | Leopold Zima v Ivan Kazakov | 6-0,6-3 |
| ITF M25 Poznan | 2021/08/22 08:00 | Thijmen Loof v Peters, Flemming | 5-7,3-6 |
| ITF M15 Oldenzaal | 2021/08/15 07:30 | Eisinga, Zachary v Peters, Flemming | 6-0,6-3 |
| Sarajevo, Singles Main, M-ITF-BIH-05A | 2021/05/30 10:30 | Galik, Matej v Peters, Flemming | 6-1,4-6,10-8 |
| ITF - M25 Kiseljak | 2021/05/24 12:15 | Breut, Lilian v Peters, Flemming | 2-6,6-3,10-7 |
| ITF - M25 Kiseljak | 2021/05/23 13:15 | Peters, Flemming v Maxim Krapivin | 3-6,7-5,10-6 |
| ITF M15 Troisdorf | 2021/05/10 08:00 | Peters, Flemming v Sidane Pontjodikromo | 4-6,1-6 |
| ITF M15 Troisdorf | 2021/05/09 08:00 | Maurus Malgiaritta v Peters, Flemming | 6-2,3-6,8-10 |
| ITF - M15 Antalya | 2021/05/04 07:00 | Peters, Flemming v Karl Friberg | 3-6,5-7 |