Stadium: Court 5 Round: 25 Ground: Clay
| UTR Pro Tennis Series Copenhagen | 2021/06/19 10:00 | Daniel De Jonge v Marius Ruzgas | 3-6,7-6,6-1 |
| UTR Pro Tennis Series Copenhagen | 2021/06/18 12:30 | Philip Hjorth v Marius Ruzgas | 6-4,1-6,3-6 |
| UTR Pro Tennis Series Copenhagen | 2021/06/17 12:30 | Ludvig Aaes v Marius Ruzgas | 2-6,6-6 |
| UTR Pro Tennis Series Copenhagen | 2021/06/15 11:00 | Dominik Palan v Marius Ruzgas | 3-6,4-5 |
| UTR Pro Tennis Series Copenhagen | 2021/06/14 09:30 | Marius Ruzgas v Warren Sinius | 6-2,6-0 |
| ITF M15 Monastir | 2021/04/26 09:00 | Marius Ruzgas v Viktor Jovic | 3-6,3-6 |
| ITF M15 Monastir | 2021/04/25 12:30 | Marius Ruzgas v Mhamed Affes | 6-1,6-2 |
| ITF M15 Monastir | 2021/04/18 13:00 | Lorenzo Bresciani v Marius Ruzgas | 7-6,6-3 |
| ITF M15 Esch/Alzette | 2021/07/22 13:10 | Tommaso Compagnucci v Alexander Kotzen | 6-2,6-0 |
| ITF M15 Esch/Alzette | 2021/07/21 10:55 | Alexander Kotzen v Louis Wessels | 2-6,6-3,6-4 |
| ITF M15 Esch/Alzette | 2021/07/20 11:00 | Benjamin Dhoe v Alexander Kotzen | 3-6,4-6 |
| ITF M15 Esch/Alzette | 2021/07/19 09:00 | Alexander Kotzen v Tibo Colson | 4-6,6-1,10-7 |
| ITF M15 Esch/Alzette | 2021/07/18 07:55 | Alexander Kotzen v Victor Ernaelsteen | 6-1,6-4 |
| ITF M15 Monastir | 2021/06/27 09:00 | Alexander Kotzen v Noah Lopez | 6-7,6-4,7-10 |
| ITF M15 Monastir | 2021/06/21 13:30 | Alexander Kotzen v Kody Pearson | 7-6,1-6,5-10 |
| ITF M15 Monastir | 2021/06/21 09:00 | Alexander Kotzen v Geun Jun Kim | 6-0,6-2 |