Stadium: C Round: 62
| ITF Women Toyota Qual | 2018/03/10 01:00 | Riko Sawayanagi v Himari Sato | 7-5,6-0 |
| ITF Women Mildura | 2018/03/06 01:05 | Maddison Inglis v Riko Sawayanagi | 6-0,6-2 |
| ITF Women Perth Qual | 2018/02/19 05:05 | Riko Sawayanagi v Lulu Sun | 2-6,3-6 |
| ITF Women Perth Qual | 2018/02/18 03:00 | Riko Sawayanagi v Ramu Ueda | 6-3,7-5 |
| ITF Women Perth | 2018/02/15 02:00 | Riko Sawayanagi v Mai Minokoshi | 1-6,1-6 |
| ITF Women Perth Qual | 2018/02/12 04:35 | Riko Sawayanagi v Maryna Chernyshova | 6-4,6-2 |
| ITF Women Perth Qual | 2018/02/11 02:00 | Riko Sawayanagi v Elizabeth James | 6-1,6-1 |
| ITF Women Launceston | 2018/02/06 23:00 | Alexandra Bozovic v Riko Sawayanagi | 6-0,6-3 |
| ITF Women Toyota Qual | 2018/03/10 03:00 | Saki Imamura v Mayu Iwai | 5-7,3-6 |
| ITF Women Kofu Qual | 2017/06/11 04:00 | Mayu Iwai v Aoi Ishino | 6-0,6-7,4-6 |
| ITF Women Nishi-Tama | 2017/03/19 01:00 | Yuki Kristina Chiang v Mayu Iwai | 6-2,6-2 |
| Challenger Kaohsiung Qual | 2016/06/14 03:00 | Ayano Shimizu v Mayu Iwai | 6-3,6-3 |