Mari Tanaka defeated Akiko Yonemura 3-6 6-3 6-2 in the Makinohara 25K round of 32 on grass. The upset overturned the form book — Akiko Yonemura came in leading the head-to-head 4–1. Mari Tanaka narrowed the head-to-head to 4–2.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2010-03-22 | Kofu 10K | SF | hard | Akiko Yonemura | 4-6 6-1 6-3 |
| 2007-09-10 | Tokyo 50K | R16 | hard | Mari Tanaka | 6-3 6-7(7) 6-4 |
| 2006-10-30 | Sutama 25K | R32 | clay | Akiko Yonemura | 6-1 6-2 |
| 2005-10-17 | Makinohara 25K | R16 | carpet | Akiko Yonemura | 3-6 6-4 6-2 |
| 2004-09-13 | Kyoto 10K | R16 | carpet | Akiko Yonemura | 6-7(3) 7-5 6-3 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.