Stadium: South Center Court Round: 25
| 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 |
| ITF Women Denain | 2018/07/05 11:05 | Quirine Lemoine v Mari Osaka | 4-6,0-6 |
| ITF Women Denain | 2018/07/04 08:30 | Mari Osaka v Momoko Kobori | 6-1,6-1 |
| ITF Women Perigueux | 2018/06/28 09:00 | Nadia Podoroska v Mari Osaka | 7-6,7-5 |
| ITF Women Perigueux | 2018/06/27 10:05 | Moyuka Uchijima v Mari Osaka | 4-6,6-7 |
| ITF Women Luzhou | 2018/05/30 02:30 | Siqi Cao v Mari Osaka | 6-4,7-5 |
| ITF Women Landisville Qual | 2018/08/06 14:00 | Maria Sanchez v Eri Hozumi | 5-7,5-7 |
| ITF Women Landisville Qual | 2018/08/05 16:20 | Nika Kukharchuk v Maria Sanchez | 5-7,3-6 |
| WTA San Jose Qual | 2018/07/29 19:45 | Maria Sanchez v Georgina Garcia-Perez | 6-7,6-7 |
| WTA San Jose Qual | 2018/07/28 19:35 | Aryna Sabalenka v Maria Sanchez | 6-2,5-7,4-6 |
| ITF Women Granby | 2018/07/25 14:00 | Rebecca Marino v Maria Sanchez | 4-6,6-4,6-1 |
| ITF Women Granby | 2018/07/24 19:00 | Cristiana Ferrando v Maria Sanchez | 2-6,5-7 |
| ITF Women Berkeley | 2018/07/19 22:25 | Maria Sanchez v Nicole Gibbs | 1-6,1-6 |
| ITF Women Berkeley | 2018/07/18 21:35 | Kimberly Birrell v Maria Sanchez | 2-6,2-6 |