Stadium: Court 1 Round: 62 Ground: Clay
| ITF M15 Warmbad-Villach | 2021/08/15 15:30 | Niklas Waldner v Rafael Kis Balazs | 4-6,5-7 |
| ITF M25 Bolzano | 2021/08/02 11:50 | Filippo Moroni v Niklas Waldner | 6-2,6-2 |
| ITF M25 Kottingbrunn | 2021/07/20 12:10 | Niklas Waldner v David Poljak | 7-6,2-6,6-7 |
| ITF M25 Telfs | 2021/07/11 09:00 | Jakub Katuch v Niklas Waldner | 1-6,3-6 |
| ITF M25 Most | 2021/05/24 09:00 | Niklas Waldner v Edward Hubner | 4-6,3-6 |
| ITF M25 Most | 2021/05/23 08:00 | Niklas Waldner v Milos Karol | 3-6,7-5,10-3 |
| ITF M15 Monastir | 2021/05/09 11:00 | Taisei Ichikawa v Niklas Waldner | 6-1,6-0 |
| ITF M15 Monastir | 2021/05/02 12:00 | Andrea Picchione v Niklas Waldner | 6-2,6-4 |
| ITF M15 Bad Waltersdorf | 2021/08/29 07:00 | Lukas Rohseano v Patric Prinoth | 6-3,3-6,13-11 |
| ITF M15 Warmbad-Villach | 2021/08/15 07:00 | Jakob Aichhorn v Lukas Rohseano | 6-0,6-0 |
| ITF M25 Kottingbrunn | 2021/07/19 08:00 | Pietro Mugelli v Lukas Rohseano | 6-4,6-7,10-8 |