Shiho Hisamatsu defeated Natsumi Hamamura 5-7 6-2 6-2 in the Noto 25K round of 32 on carpet. The upset overturned the form book — Natsumi Hamamura came in leading the head-to-head 4–1. Shiho Hisamatsu narrowed the head-to-head to 4–2.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2010-05-17 | Karuizawa 25K | R16 | carpet | Natsumi Hamamura | 7-6(1) 6-4 |
| 2009-08-10 | Quanzhou 25K | R32 | hard | Natsumi Hamamura | 6-3 6-3 |
| 2007-03-19 | Mumbai 25K | R16 | hard | Natsumi Hamamura | 6-1 6-1 |
| 2006-10-30 | Sutama 25K | R16 | clay | Shiho Hisamatsu | 2-6 6-0 7-6(4) |
| 2004-11-01 | Sutama 25K | SF | clay | Natsumi Hamamura | 7-6(8) 6-1 |