Stadium: Court 3 Round: 25 Ground: Clay
| ITF Turkey F33 | 2018/10/24 07:00 | Ivan Nedelko v Gabriel Donev | 7-5,1-6,6-4 |
| ITF M15 St Petersburg | 2021/04/10 08:00 | Alexander Cozbinov v Ivan Nedelko | 6-2,4-6,3-6 |
| ITF M15 St Petersburg | 2021/04/09 08:00 | Ivan Nedelko v Sarp Agabigun | 6-1,6-4 |
| ITF M15 St Petersburg | 2021/04/08 07:00 | Ivan Nedelko v Simon Freund | 6-2,6-4 |
| ITF M15 St Petersburg | 2021/04/06 09:00 | Ivan Nedelko v Petr Bar Biryukov | 6-3,6-1 |
| ITF M15 St Petersburg | 2021/04/05 08:35 | Ivan Nedelko v Martin Borisiouk | 6-2,6-1 |
| ITF M15 St Petersburg | 2021/04/04 13:20 | Ivan Nedelko v Sergei Pogosian | 6-1,6-1 |
| Challenger Oeiras | 2021/03/28 10:00 | Francisco Cabral v Ivan Nedelko | 6-2,5-7,6-4 |
| Challenger Zadar | 2021/03/25 09:30 | Nikola Milojevic v Ivan Nedelko | 6-2,6-1 |
| UTR Pro Tennis Series Pazardzhik | 2021/04/10 10:30 | Gergely Madarasz v Gabriel Donev | 4-6,6-3,6-0 |
| UTR Pro Tennis Series Pazardzhik | 2021/04/09 11:30 | Gabriel Donev v Ronan Joncour | 5-7,3-6 |
| UTR Pro Tennis Series Pazardzhik | 2021/04/07 09:30 | Gabriel Donev v Plamen Milushev | 7-5,6-3 |
| UTR Pro Tennis Series Pazardzhik | 2021/04/06 08:30 | Gabriel Donev v Yanaki Milev | 6-2,5-1 |
| UTR Pro Tennis Series Pazardzhik | 2021/04/05 13:00 | Constant De La Bassetiere v Gabriel Donev | 5-7,1-6 |
| ITF M15 Antalya | 2021/03/30 07:00 | Gabriel Donev v Diego A B Sanchez | 4-6,6-1,7-10 |
| ITF M15 Antalya | 2021/03/29 07:00 | Gabriel Donev v Stefanos Sakellaridis | 6-3,5-7,10-2 |
| ITF M15 Antalya | 2021/03/28 06:30 | Gabriel Donev v Mikail Alimli | 6-1,6-2 |