Stadium: Centre Round: 28 Ground: Grass
| Challenger Yokohama Qual | 2017/02/27 01:00 | Brydan Klein v Shuichi Sekiguchi | 7-5,6-2 |
| Challenger Kobe | 2018/11/13 07:50 | Jordi Samper-Montana v Shuichi Sekiguchi | 6-4,6-1 |
| ITF Vietnam F4 | 2018/10/25 03:00 | Shuichi Sekiguchi v Filip Bergevi | 3-6,4-6 |
| ITF Vietnam F4 | 2018/10/23 05:20 | Shuichi Sekiguchi v Billy Harris | 7-6,4-6,7-6 |
| ITF Slovakia F3 | 2018/08/07 11:25 | Samm Butler v Shuichi Sekiguchi | 6-1,7-6 |
| ITF Austria F3 | 2018/07/16 08:00 | Jorge Panta v Shuichi Sekiguchi | 1-6,7-6,7-5 |
| ITF Czech Republic F6 | 2018/07/10 08:00 | Martin Bugaj v Shuichi Sekiguchi | 6-1,6-2 |
| ITF China F9 | 2018/07/06 03:00 | Min-Kyu Song v Shuichi Sekiguchi | 6-2,6-1 |
| ITF China F9 | 2018/07/05 04:35 | Chenhe Li v Shuichi Sekiguchi | 2-6,5-7 |
| Challenger Canberra 2 | 2018/10/30 00:45 | Maxime Janvier v Brydan Klein | 6-4,6-3 |
| Challenger Canberra 2 | 2018/10/28 02:05 | Tung-Lin Wu v Brydan Klein | 6-7,4-6 |
| Challenger Canberra 2 | 2018/10/27 04:40 | Edward Bourchier v Brydan Klein | 2-6,1-6 |
| Challenger Canberra 2 | 2018/10/27 01:20 | Tomislav E Papac v Brydan Klein | 0-6,3-6 |
| Challenger Traralgon | 2018/10/26 01:30 | Brydan Klein v Marc Polmans | 3-6,4-6 |
| Challenger Traralgon | 2018/10/24 01:40 | Jason Kubler v Brydan Klein | 4-6,7-6,3-6 |
| Challenger Traralgon | 2018/10/23 02:10 | Jeremy Beale v Brydan Klein | 6-7,6-7 |
| Challenger Traralgon | 2018/10/21 23:00 | Francesco Vilardo v Brydan Klein | 7-5,2-6,2-6 |