The US Open champion was trailing 6-3 when she retired with an upper left leg injury.
| year | Event | RND | Winner | Results |
|---|---|---|---|---|
| 2018 |
BNP Paribas WTA Finals Singapore Red Group
|
Championship | Kiki Bertens |
3-6
0-0 |
| 2018 |
BNP Paribas WTA Finals Singapore Red Group
|
Championship | Angelique Kerber |
6-4
5-7 6-4 |
| 2018 |
BNP Paribas WTA Finals Singapore Red Group
|
Championship | Sloane Stephens |
5-7
6-4 1-6 |
| 2018 |
China Open
|
Semi Finals | Anastasija Sevastova |
6-4
6-4 |
| 2018 |
China Open
|
Quarter Finals | Naomi Osaka |
6-3
4-6 5-7 |
| 2018 |
China Open
|
1/8 | Naomi Osaka |
1-6
2-6 |
| 2018 |
China Open
|
1/16 | Naomi Osaka |
1-6
0-6 |
| 2018 |
China Open
|
1/32 | Naomi Osaka |
4-6
3-6 |
| 2018 |
Pan Pacific Open
|
Final | Karolina Pliskova |
4-6
4-6 |
| 2018 |
Pan Pacific Open
|
Semi Finals | Naomi Osaka |
2-6
3-6 |
| 2018 |
Pan Pacific Open
|
Quarter Finals | Naomi Osaka |
6-3
6-4 |
| 2018 |
Pan Pacific Open
|
1/8 | Naomi Osaka |
6-2
6-1 |
| year | Event | RND | Winner | Results |
|---|---|---|---|---|
| 2018 |
Swiss Indoors Basel, Qualification
|
1/8 | Marius Copil |
7-5
7-5 |
| 2018 |
VTB Kremlin Cup
|
1/16 | Benoit Paire |
7-6
2-6 6-1 |
