Mari Osaka defeated Peggy Porter 6-1 6-3 in the Port St Lucie FL 25K round of 32 on clay. The upset overturned the form book — Peggy Porter came in leading the head-to-head 1–0. Mari Osaka claimed a first win over Peggy Porter in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2013-06-03 | Las Cruces NM 25K | R32 | hard | Peggy Porter | 6-1 6-7(3) 6-2 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.