Stadium: Court 2 Round: 25 Ground: Carpet indoor
| Czech Republic F2, Singles | 2017/05/28 08:30 | Mertl, Jan v Lenz, Julian | 6-4,2-6,2-6 |
| ITF Switzerland F1 | 2018/02/06 14:45 | Mertl, Jan v Alexander Ritschard | 6-2,6-7,6-7 |
| ITF Germany F2 | 2018/01/25 10:00 | Mertl, Jan v Pedro Cachin | 6-4,4-6,5-7 |
| ITF Germany F2 | 2018/01/24 14:50 | Mertl, Jan v Krawietz, Kevin | 4-6,7-6,6-1 |
| Czech Extraliga, Men | 2017/12/17 11:40 | Mertl, Jan v Kamke, Tobias | 7-6,2-6,6-7 |
| Czech Extraliga, Men | 2017/12/16 13:41 | Gojowczyk, Peter v Mertl, Jan | 6-3,6-6 |
| Czech Extraliga, Men | 2017/12/16 10:20 | Gojowczyk, Peter v Mertl, Jan | 6-3,7-6 |
| Challenger Bratislava Qual | 2017/11/06 11:20 | Farquharson, Tom v Mertl, Jan | 7-6,6-3 |
| Challenger Bratislava Qual | 2017/11/05 12:40 | Samuel Puskar v Mertl, Jan | 4-6,3-6 |
| ITF Switzerland F1 | 2018/02/09 13:00 | Lenz, Julian v Simon, Tobias | 6-7,4-6 |
| ITF Switzerland F1 | 2018/02/08 12:00 | Albano Olivetti v Lenz, Julian | 7-5,5-7,6-7 |
| ITF Switzerland F1 | 2018/02/06 12:00 | Haerteis, Johannes v Lenz, Julian | 6-2,1-6,4-6 |
| ITF Germany F2 | 2018/01/23 11:30 | Lenz, Julian v Botic Van De Zandschulp | 6-7,3-6 |
| Challenger Koblenz Qual | 2018/01/14 12:25 | Pedro Cachin v Lenz, Julian | 6-1,6-3 |
| ITF Turkey F47 | 2017/12/15 07:15 | Wang, Tak Khunn v Lenz, Julian | 6-4,6-3 |
| ITF Turkey F47 | 2017/12/14 08:50 | Gore, Kaya v Lenz, Julian | 2-6,1-6 |
| ITF Turkey F47 | 2017/12/12 07:15 | Chadaj, Adam v Lenz, Julian | 6-3,3-6,6-7 |