Stadium: Indoor 2 Round: 25 Ground: Hardcourt outdoor
| ITF M15 Kouvola | 2021/05/25 09:10 | Jonas Maier v Oskar Stumpf | 6-3,6-0 |
| ITF M15 Troisdorf | 2021/05/11 11:05 | Jonas Maier v Timo Stodder | 2-6,1-6 |
| ITF M15 Troisdorf | 2021/05/10 11:00 | Buvaysar Gadamauri v Jonas Maier | 5-7,6-4,4-10 |
| ITF M15 Troisdorf | 2021/05/09 10:00 | Jonas Maier v Stefan Loncar | 6-2,3-6,10-8 |
| ITF M15 Monastir | 2021/04/12 08:00 | Jonas Maier v Amaury Raynel | 4-6,2-6 |
| ITF M15 Monastir | 2021/04/11 09:00 | Simon Sedliak v Jonas Maier | 2-6,4-6 |
| UTR Pro Tennis Series California | 2021/02/20 17:30 | Jonas Maier v Keenan Mayo | 5-7,0-0 |
| UTR Pro Tennis Series California | 2021/02/19 16:00 | Joshua Ortlip v Jonas Maier | 6-7,6-2,5-4 |
| ITF M15 Heraklion | 2021/05/20 12:10 | Alexandros Skorilas v Joao Victor C Loureiro | 6-0,7-5 |
| ITF M15 Heraklion | 2021/05/19 11:00 | Wishaya Trongcharoenchaikul v Joao Victor C Loureiro | 3-6,6-3,6-7 |