Justyna Jegiolka defeated Aki Yamasoto 2-6 6-2 6-0 in the Waterloo 50K round of 32 on clay. The upset overturned the form book — Aki Yamasoto came in leading the head-to-head 2–0. Justyna Jegiolka claimed a first win over Aki Yamasoto in three meetings, narrowing the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2012-05-21 | Karuizawa 25K | R32 | grass | Aki Yamasoto | 6-2 6-2 |
| 2012-05-07 | Fukuoka 50K | Q16 | grass | Aki Yamasoto | 4-6 6-2 6-1 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.