Stadium: Ochsenhausen, Germany
| Challenger Series TT | 2023/05/29 13:10 | Peter Hribar v Karl Zimmermann | L | 3-0 |
| Challenger Series TT | 2023/05/29 10:30 | Dauud Cheaib v Karl Zimmermann | L | 3-0 |
| Challenger Series TT | 2023/05/29 07:50 | Carlo Rossi v Karl Zimmermann | L | 3-0 |
| Challenger Series TT | 2023/03/10 11:30 | Karl Zimmermann v Dillon Chambers | L | 1-3 |
| Challenger Series TT | 2023/03/10 08:50 | Karl Zimmermann v Guilherme Teodoro | L | 1-3 |
| Challenger Series TT | 2023/03/09 20:10 | Karl Zimmermann v Thibault Poret | L | 0-3 |
| Challenger Series TT | 2023/03/09 15:30 | Karl Zimmermann v Damian Zech | W | 3-0 |
| Challenger Series TT | 2023/03/09 13:30 | Karl Zimmermann v Samuel Amann | W | 3-0 |
| Challenger Series TT | 2023/05/29 15:10 | Peter Hribar v Ryoichi Yoshiyama | W | 1-3 |
| Challenger Series TT | 2023/05/29 13:50 | Dauud Cheaib v Ryoichi Yoshiyama | W | 0-3 |
| Challenger Series TT | 2023/05/29 09:50 | Carlo Rossi v Ryoichi Yoshiyama | L | 3-0 |
| Challenger Series TT | 2023/05/29 07:10 | Simon Berglund v Ryoichi Yoshiyama | L | 3-2 |
| Japan T League | 2023/02/18 03:30 | Kakeru Sone v Ryoichi Yoshiyama | W | 2-3 |
| WTT Contender Amman Quals 2023 | 2023/02/08 09:30 | Cheng-Jui Kao v Ryoichi Yoshiyama | L | 3-2 |
| WTT Contender Amman Quals 2023 | 2023/02/07 14:20 | Ryoichi Yoshiyama v Tingyu Wang | W | 3-1 |
| WTT Contender Amman Quals 2023 | 2023/02/06 15:10 | David Serdaroglu v Ryoichi Yoshiyama | W | 1-3 |