Stadium: Court 2 Round: 26 Ground: Hardcourt outdoor
| Challenger Heilbronn | 2021/05/09 11:55 | Christoph Negritu v Aleksandar Vukic | 5-7,2-6 |
| ITF M15 Monastir | 2021/04/25 08:30 | Igor Marcondes v Christoph Negritu | 2-6,2-6 |
| ITF M15 Monastir | 2021/04/24 09:30 | Omar Giacalone v Christoph Negritu | 4-6,2-6 |
| ITF M15 Monastir | 2021/04/22 10:35 | Christoph Negritu v Christian Langmo | 7-5,7-6 |
| ITF M15 Monastir | 2021/04/20 11:15 | Danylo Kalenichenko v Christoph Negritu | 2-6,4-6 |
| ITF M15 Monastir | 2021/04/14 12:05 | Christoph Negritu v Savva Polukhin | 5-7,4-6 |
| ITF M15 Monastir | 2021/04/10 08:30 | Franco Agamenone v Christoph Negritu | 6-1,6-3 |
| ITF M15 Monastir | 2021/04/08 11:25 | Mateus Alves v Christoph Negritu | 4-6,4-6 |
| ITF M15 Monastir | 2021/06/20 09:00 | Kazuki Nishiwaki v Raphael Lambling | 3-6,4-6 |
| ITF M15 Monastir | 2021/06/13 08:00 | Kazuki Nishiwaki v Kody Pearson | 4-6,2-6 |
| ITF M15 Monastir | 2021/06/07 09:00 | Kazuki Nishiwaki v Dong Ju Kim | 2-6,3-6 |
| ITF M25 Nonthaburi | 2020/02/02 06:00 | Reese Stalder v Kazuki Nishiwaki | 7-6,7-5 |
| ITF M25 Nonthaburi | 2020/01/26 02:30 | Kazuki Nishiwaki v Rimpei Kawakami | 6-7,2-6 |
| Challenger Kobe | 2019/11/04 08:30 | Kazuki Nishiwaki v Yosuke Watanuki | 3-6,4-6 |
| Challenger Kobe | 2019/11/04 01:30 | Kazuki Nishiwaki v Timur Khabibulin | 3-6,1-6 |
| ITF M25 Tay Ninh | 2019/10/10 05:00 | Billy Harris v Kazuki Nishiwaki | 6-4,6-4 |