Osaka is the frontrunner; she's the only one who could lose in the semis and become No. 1.
| year | Event | RND | Winner | Results |
|---|---|---|---|---|
| 2019 |
Australian Open WTA
|
1/8 | Serena Williams |
1-6
6-4 4-6 |
| 2019 |
Australian Open WTA
|
1/16 | Simona Halep |
6-2
6-3 |
| 2019 |
Australian Open WTA
|
1/32 | Simona Halep |
6-3
6-7 6-4 |
| 2019 |
Australian Open WTA
|
1/64 | Simona Halep |
6-7
6-4 6-2 |
| 2019 |
Sydney International
|
1/8 | Ashleigh Barty |
4-6
4-6 |
| year | Event | RND | Winner | Results |
|---|---|---|---|---|
| 2017 |
TEB BNP Paribas Istanbul Cup, Qualification
|
1/12 (Special Qual) | Alla Kudryavtseva |
6-3
6-2 |
