Stadium: Center Court Round: 19 Ground: Hardcourt outdoor
| Iasi, Romania | 2020/09/12 09:00 | Haerteis, Johannes v Alexandar Lazarov | 3-6,5-7 |
| ITF Austria F2 | 2018/07/12 11:15 | Alexandar Lazarov v Haerteis, Johannes | 3-6,2-6 |
| Challenger Manama | 2021/11/21 10:05 | Haerteis, Johannes v Ammar Faleh Alhogbani | 6-2,6-1 |
| Helsinki, Finland | 2021/11/14 09:00 | Haerteis, Johannes v Viktor Durasovic | 4-6,6-7 |
| Challenger Eckental | 2021/11/02 18:15 | Maxime Cressy v Haerteis, Johannes | 6-7,6-4,6-3 |
| Challenger Eckental | 2021/11/01 11:15 | Haerteis, Johannes v Ignatik, Uladzimir | 4-6,6-2,7-6 |
| Challenger Eckental | 2021/10/31 13:30 | Lucas Miedler v Haerteis, Johannes | 3-6,7-5,3-6 |
| Challenger Ismaning | 2021/10/25 11:50 | Otto Virtanen v Haerteis, Johannes | 4-6,6-3,6-3 |
| Challenger Ismaning | 2021/10/24 12:35 | Haerteis, Johannes v Tristan Lamasine | 6-4,6-4 |
| ITF M25 Hamburg | 2021/10/23 10:00 | Henri Squire v Haerteis, Johannes | 6-4,6-4 |
| Challenger Manama | 2021/11/21 10:00 | Cozbinov, Alexander v Alexandar Lazarov | 1-6,2-6 |
| Challenger Bratislava | 2021/11/07 15:55 | Alexandar Lazarov v Alexander Shevchenko | 6-4,5-7,3-6 |
| Challenger Lima | 2021/10/26 17:20 | Alejandro Tabilo v Alexandar Lazarov | 6-1,6-4 |
| Challenger Lima | 2021/10/25 17:00 | Lucas Catarina v Alexandar Lazarov | 4-6,2-6 |
| Challenger Lima | 2021/10/24 16:00 | Luca Castelnuovo v Alexandar Lazarov | 4-6,5-7 |
| Bogota, Colombia | 2021/10/17 16:30 | Alexandar Lazarov v Stevens, Bart | 6-1,3-6,3-6 |
| ITF M15 Sozopol | 2021/10/08 07:00 | Alexandar Lazarov v Billy Harris | 4-6,2-6 |
| ITF M15 Sozopol | 2021/10/07 07:00 | Alexandar Lazarov v Adam Jurajda | 6-1,6-4 |