By surface
| Surface | Hietala | John Tregonning |
|---|---|---|
| Hard | 1 | 5 |
All meetings (6)
| Date | Tour | Tournament | Round | Surface | Winner | Set 1 | Set 2 | Set 3 | Set 4 | Set 5 |
|---|---|---|---|---|---|---|---|---|---|---|
| 2019-01-14 | WTA | Australian Open | Round of 128 | Hard | Shuai Zhang | 2-6 | 6-4 | 2-6 | ||
| 2017-01-02 | WTA | Brisbane | Round of 16 | Hard | Dominika Cibulkova | 6-2 | 4-6 | 4-6 | ||
| 2014-02-24 | WTA | Acapulco | Semifinal | Hard | Dominika Cibulkova | 2-4 | ||||
| 2011-10-03 | WTA | Beijing | Round of 64 | Hard | Dominika Cibulkova | 0-6 | 2-6 | |||
| 2011-08-29 | WTA | US Open | Round of 128 | Hard | Dominika Cibulkova | 3-6 | 4-6 | |||
| 2010-02-06 | WTA | Fed Cup WG2 R1: SVK vs CHN | Round Robin | Hard | Dominika Cibulkova | 4-6 | 1-6 |