Stadium: Court 9 Round: 14 Ground: Hardcourt outdoor
| Challenger Seville | 2021/09/08 20:05 | Roberto Carballes Baena v Adrian Andreev | 6-4,6-1 |
| Challenger Seville | 2021/09/06 19:00 | Roberto Ortega-Olmedo v Adrian Andreev | 6-7,0-6 |
| Challenger Luedenscheid | 2021/08/15 11:00 | Matteo Martineau v Adrian Andreev | 6-4,7-5 |
| Challenger Prague | 2021/08/10 11:45 | Adrian Andreev v Nino Serdarusic | 3-6,3-6 |
| Challenger Prague | 2021/08/09 09:55 | Adrian Andreev v Facundo Diaz Acosta | 2-6,6-4,6-3 |
| Challenger Prague | 2021/08/08 12:00 | Adrian Andreev v Aldin Setkic | 7-5,6-1 |
| Challenger Segovia | 2021/07/26 16:30 | Adrian Andreev v Benjamin Bonzi | 7-6,4-6,6-7 |
| Challenger Pozoblanco | 2021/07/21 15:00 | Adrian Andreev v Gregoire Barrere | 3-6,0-6 |
| ITF M25 Trier | 2021/08/26 09:30 | Tim Handel v Alexander Cozbinov | 6-2,3-6,6-2 |
| ITF M25 Trier | 2021/08/24 15:30 | Alexander Cozbinov v Laurent Lokoli | 6-2,3-6,7-6 |
| ITF M25 Ueberlingen | 2021/08/19 10:00 | Alexander Cozbinov v Tim Handel | 3-6,4-6 |
| ITF M25 Ueberlingen | 2021/08/18 10:10 | Jeremy Jahn v Alexander Cozbinov | 3-6,7-6,1-6 |
| Challenger Segovia | 2021/07/26 09:00 | Alexander Cozbinov v Dalibor Svrcina | 1-6,6-2,2-6 |
| Challenger Segovia | 2021/07/25 09:00 | Federico Zeballos v Alexander Cozbinov | 1-6,1-6 |
| ITF M25 Idanha-A-Nova | 2021/07/22 08:00 | Alexander Cozbinov v Nicolas Moreno De Alboran | 6-3,6-7,6-7 |
| ITF M25 Idanha-A-Nova | 2021/07/21 11:35 | Alexander Cozbinov v Mehluli D A Sibanda | 6-3,6-0 |