Stadium: Court 6 Round: 54 Ground: Clay
| ITF M15 Parnu | 2021/08/04 09:20 | Vladimir Ivanov v Milan Welte | 7-5,1-6,6-3 |
| ITF M25 Marburg | 2021/07/09 12:00 | Ryan Nijboer v Milan Welte | 4-6,6-3,6-1 |
| ITF M25 Marburg | 2021/07/08 08:55 | Milan Welte v Neo Niedner | 6-2,6-1 |
| ITF M25 Marburg | 2021/07/07 12:30 | Daniel Cukierman v Milan Welte | 4-6,4-6 |
| ITF M25 Marburg | 2021/07/06 15:00 | Milan Welte v Raphael Collignon | 7-6,6-3 |
| ITF M25 Marburg | 2021/07/05 13:05 | Milan Welte v Christopher Patzanovsky | 6-1,6-3 |
| ITF M15 Heraklion | 2021/05/17 07:00 | Milan Welte v Tom Gentzsch | 6-0,6-3 |
| ITF M15 Troisdorf | 2021/05/09 13:00 | Yannik Steinegger v Milan Welte | 6-4,6-2 |
| ITF M15 Novi Sad | 2021/08/02 11:00 | Ivailo Keremedchiev v Taiyo Yamanaka | 6-2,6-7,10-6 |
| ITF M15 Novi Sad | 2021/08/01 11:15 | Luka Kalenic v Taiyo Yamanaka | 0-6,1-6 |
| ITF M15 Novi Sad | 2021/07/25 07:00 | Stevan Popovic v Taiyo Yamanaka | 6-3,4-6,10-7 |
| ITF M25 Kottingbrunn | 2021/07/21 12:05 | Taiyo Yamanaka v Sandro Kopp | 1-6,2-6 |
| ITF M25 Kottingbrunn | 2021/07/20 07:55 | Taiyo Yamanaka v Benedikt Emesz | 7-6,5-7,8-10 |
| ITF M25 Kottingbrunn | 2021/07/19 08:00 | Taiyo Yamanaka v Michal Novansky | 7-5,4-6,11-9 |
| ITF M25 Kottingbrunn | 2021/07/18 07:30 | Taiyo Yamanaka v Leon Benedict | 6-4,6-1 |
| ITF M25 Telfs | 2021/07/13 09:10 | Taiyo Yamanaka v George Botezan | 1-6,1-6 |