Stadium: Court 2 Round: 62 Ground: Clay
| ITF - Haga M25 | 2021/06/27 08:00 | Dax Donders v Zachary Eisinga | 6-2,7-5 |
| ITF - Alkmaar M25 | 2021/06/21 14:25 | Guillaume Dermiens v Zachary Eisinga | 4-6,7-5,13-11 |
| ITF - Alkmaar M25 | 2021/06/20 12:30 | Lodewijk Weststrate v Zachary Eisinga | 2-6,1-6 |
| ITF - Cairo M15 | 2021/05/04 08:00 | Zachary Eisinga v Martin Dimitrov | 1-6,6-7 |
| ITF - Cairo M15 | 2021/05/03 08:00 | Zachary Eisinga v Ali Alshati | 3-6,6-0,10-8 |
| ITF - Cairo M15 | 2021/04/28 10:00 | Zachary Eisinga v Shintaro Mochizuki | 4-6,2-6 |
| ITF - Cairo M15 | 2021/04/19 10:30 | Zachary Eisinga v Fares Zakaria | 2-6,6-3,3-10 |
| ITF - Cairo M15 | 2021/04/18 07:00 | Zachary Eisinga v Anton Magnusson | 6-2,4-6,10-2 |
| ITF - Sarajewo M15 | 2021/05/30 10:30 | Matej Galik v Flemming Peters | 6-1,4-6,10-8 |
| ITF - Kiseljak M25 | 2021/05/24 12:15 | Lilian Breut v Flemming Peters | 2-6,6-3,10-7 |
| ITF - Kiseljak M25 | 2021/05/23 13:15 | Flemming Peters v Maxim Krapivin | 3-6,7-5,10-6 |
| ITF - Troisdorf M15 | 2021/05/10 08:00 | Flemming Peters v Sidane Pontjodikromo | 4-6,1-6 |
| ITF - Troisdorf M15 | 2021/05/09 08:00 | Maurus Malgiaritta v Flemming Peters | 6-2,3-6,8-10 |
| ITF - Antalya M15 | 2021/05/04 07:00 | Flemming Peters v Karl Friberg | 3-6,5-7 |
| ITF - Antalya M15 | 2021/04/25 07:00 | Flemming Peters v Vojtech Mares | 3-6,3-6 |
| ITF - Meerbusch M25 | 2021/04/11 13:30 | Alexis Boureau v Flemming Peters | 6-7,6-3,10-8 |