Stadium: Court 3 Round: 25 Ground: Clay
| ITF M15 Sofia | 2023/07/04 09:40 | Gabriel Donev v Denis Klok | 5-7,1-6 |
| ITF M15 Pazardzhik | 2023/05/20 07:00 | Gabriel Donev v Denis Klok | 6-7,5-7 |
| Challenger Banja Luka | 2023/08/07 14:00 | Eric Vanshelboim v Denis Klok | 6-3,6-0 |
| Challenger Banja Luka | 2023/08/07 11:05 | Denys Molchanov v Denis Klok | 1-6,4-6 |
| Challenger Liberec | 2023/07/31 11:00 | Federico Agustin Gomez v Denis Klok | 6-3,6-2 |
| Challenger Liberec | 2023/07/30 14:10 | Sebastian Dominko v Denis Klok | 6-7,5-7 |
| Challenger Amersfoort | 2023/07/17 09:00 | Tibo Colson v Denis Klok | 6-4,6-2 |
| Challenger Amersfoort | 2023/07/16 10:50 | Denis Klok v Hady Habib | 3-6,7-5,6-1 |
| ITF M15 Sofia | 2023/07/08 09:35 | Goncalo Oliveira v Denis Klok | 6-3,6-4 |
| ITF M15 Sofia | 2023/07/06 08:10 | Adam Heinonen v Denis Klok | 1-6,1-6 |
| ITF M15 Kursumlijska Banja | 2023/08/30 09:05 | Gabriel Donev v Alessandro Bellifemine | 3-6,6-4,2-6 |
| ITF M15 Targu Jiu | 2023/08/15 13:45 | Lorenzo Joaquin Rodriguez v Gabriel Donev | 6-7,7-6,6-4 |
| ITF M15 Curtea de Arges | 2023/08/09 10:35 | Gabriel Donev v Luciano Emanuel Ambrogi | 0-6,4-6 |
| ITF M25 Pitesti | 2023/08/01 06:30 | Gabriel Donev v Quentin Folliot | 6-4,5-7,1-6 |
| ITF M15 Sofia | 2023/07/04 09:40 | Gabriel Donev v Denis Klok | 5-7,1-6 |
| ITF M15 Belgrade | 2023/06/28 12:30 | Miljan Zekic v Gabriel Donev | 6-4,6-3 |
| ITF M15 Kursumlijska Banja | 2023/06/17 17:15 | Gabriel Donev v Marat Sharipov | 3-6,4-6 |
| ITF M15 Kursumlijska Banja | 2023/06/17 12:00 | Lautaro Midon v Gabriel Donev | 0-6,5-7 |