Stadium: Court 1 Round: 26 Ground: Clay
| ITF Japan F8 | 2016/06/16 02:15 | Watanuki, Keisuke v Katayama, Sho | 3-6,1-6 |
| ITF Japan F5 | 2016/04/06 03:40 | Watanuki, Keisuke v Katayama, Sho | 2-6,5-7 |
| ITF Japan F6 | 2014/06/11 07:50 | Katayama, Sho v Watanuki, Keisuke | 6-3,7-5 |
| ITF Japan F8 | 2018/06/12 01:00 | Katayama, Sho v Inoue, Haru | 6-1,6-4 |
| ITF China F8 | 2018/06/08 04:10 | Katayama, Sho v Ehara, Hiroyasu | 0-6,2-6 |
| ITF China F8 | 2018/06/06 02:00 | Katayama, Sho v Yin, Bang Shuo | 6-2,6-4 |
| ITF China F8 | 2018/06/04 03:50 | Katayama, Sho v Wu, Hao | 6-2,6-2 |
| ITF Japan F6 | 2018/04/11 01:00 | Katayama, Sho v Li, Zhe | 1-6,6-3,4-6 |
| ITF Japan F5 | 2018/04/03 04:10 | Katayama, Sho v Renta Tokuda | 2-6,4-6 |
| ITF Japan F4 | 2018/03/30 03:30 | Katayama, Sho v Yosuke Watanuki | 4-6,4-6 |
| ITF Japan F4 | 2018/03/29 03:45 | Katayama, Sho v Tamaki Yamao | 6-4,6-4 |
| ITF Japan F8 | 2018/06/12 01:00 | Watanuki, Keisuke v Uesugi, Teppei | 6-3,6-3 |
| ITF Japan F8 | 2018/06/11 00:30 | Watanuki, Keisuke v Daisuke Sumizawa | 6-4,2-6,6-2 |
| ITF Japan F3 | 2018/03/17 00:30 | Watanuki, Keisuke v Numajiri, Keisuke | 3-6,1-6 |
| Challenger Kyoto Qual | 2018/02/17 01:00 | Watanuki, Keisuke v Shibano, Kosuke | 4-6,4-6 |
| ITF Japan F8 | 2017/06/15 02:30 | Watanuki, Keisuke v Ehara, Hiroyasu | 1-6,3-6 |
| ITF Japan F8 | 2017/06/14 05:50 | Kishi, Ryota v Watanuki, Keisuke | 0-6,1-6 |
| ITF Japan F8 | 2017/06/12 00:00 | Watanuki, Keisuke v Kazuki Nishiwaki | 6-2,6-2 |
| ITF Japan F8 | 2017/06/10 04:00 | Watanuki, Keisuke v Taketo Takamisawa | 4-6,6-2,6-3 |