Stadium: M Round: 45 Ground: Hardcourt outdoor
| ITF Women Nantes | 2017/10/31 12:05 | Antonia Lottner v Mari Osaka | 2-6,2-6 |
| ITF Women Montreux | 2018/09/07 13:00 | Kimberley Zimmermann v Mari Osaka | 7-5,6-4 |
| ITF Women Montreux | 2018/09/06 08:00 | Mari Osaka v Martina Trevisan | 6-3,6-2 |
| ITF Women Montreux | 2018/09/04 09:30 | Mari Osaka v Monika Kilnarova | 6-2,6-1 |
| ITF Women Budapest | 2018/08/25 12:40 | Mari Osaka v Maria Marfutina | 1-6,2-6 |
| ITF Women Braunschweig | 2018/08/22 09:00 | Anastasia Zarycka v Mari Osaka | 6-4,7-5 |
| ITF Women Porto | 2018/07/24 09:30 | Lisa Sabino v Mari Osaka | 6-2,6-1 |
| WTA Bucharest Qual | 2018/07/14 11:15 | Claire Liu v Mari Osaka | 6-0,3-6,6-4 |
| ITF Women Denain | 2018/07/06 09:00 | Aliona Bolsova Zadoinov v Mari Osaka | 6-1,6-4 |
| WTA Hiroshima | 2018/09/09 05:20 | Antonia Lottner v Yuxuan Zhang | 3-6,4-6 |
| US Open Women | 2018/08/23 15:00 | Francesca Di Lorenzo v Antonia Lottner | 6-4,7-5 |
| US Open Women | 2018/08/21 18:05 | Antonia Lottner v Viktoriya Tomova | 6-1,6-1 |
| ITF Women Hechingen | 2018/08/09 15:30 | Tamara Korpatsch v Antonia Lottner | 6-4,6-0 |
| ITF Women Hechingen | 2018/08/08 11:00 | Tereza Martincova v Antonia Lottner | 4-6,0-6 |
| ITF Women Bad Saulgau | 2018/08/02 09:00 | Antonia Lottner v Alexandra Cadantu | 6-1,2-6,4-6 |
| ITF Women Bad Saulgau | 2018/08/01 10:30 | Antonia Lottner v Miriam Kolodziejova | 7-6,6-3 |
| ITF Women Bad Saulgau | 2018/07/31 15:30 | Antonia Lottner v Miriam Kolodziejova | 7-6,5-3 |