| WTT Star Contender - Bangkok - Calificari | 2023/04/24 11:40 | Kay Stumper v Cheng-Jui Kao | L | 0-3 |
| WTT Feeder - Panagyurishte | 2023/08/31 17:00 | Kay Stumper v Pavel Sirucek | W | 3-2 |
| WTT Contender - Rio - Calificari | 2023/08/08 19:40 | Ricardo Walther v Kay Stumper | L | 3-2 |
| WTT Contender - Rio - Calificari | 2023/08/07 21:20 | Carlo Rossi v Kay Stumper | W | 2-3 |
| WTT - Contender Lima - Calificari | 2023/08/02 21:35 | Kay Stumper v Ricardo Walther | L | 1-3 |
| WTT - Contender Lima - Calificari | 2023/08/01 23:30 | Kay Stumper v Eduardo Mendoza | W | 3-0 |
| WTT Contender - Zagreb - Calificari | 2023/06/26 16:50 | Kay Stumper v Vincent Picard | L | 0-3 |
| WTT - Contender Tunis - Calificari | 2023/06/21 10:45 | Florent Lambiet v Kay Stumper | L | 3-1 |
| WTT - Contender Tunis - Calificari | 2023/06/20 11:45 | Tamas Lakatos v Kay Stumper | W | 1-3 |
| WTT Feeder - Panagyurishte | 2023/08/31 17:35 | Andrea Puppo v Cheng-Jui Kao | W | 1-3 |
| WTT Feeder - Olomouc | 2023/08/25 09:45 | Zheng Sun v Cheng-Jui Kao | L | 3-1 |
| WTT Feeder - Olomouc | 2023/08/24 14:00 | Hyeonggyu Woo v Cheng-Jui Kao | W | 1-3 |
| WTT - Contender Rio | 2023/08/11 17:20 | Dimitrij Ovtcharov v Cheng-Jui Kao | L | 3-0 |
| WTT - Contender Rio | 2023/08/10 19:35 | Cheng-Jui Kao v Daeseong Cho | W | 3-2 |
| WTT - Contender Lima | 2023/08/06 22:55 | Marcos Freitas v Cheng-Jui Kao | L | 4-1 |
| WTT - Contender Lima | 2023/08/06 00:40 | Dang Qiu v Cheng-Jui Kao | W | 1-3 |
| WTT - Contender Lima | 2023/08/05 17:15 | Cheng-Jui Kao v Alvaro Robles | W | 3-1 |