Masato Hatanaka defeated Tasuku Iwami 6-3 6-3 in the Japan F12 round of 32 on hard. The upset overturned the form book — Tasuku Iwami came in leading the head-to-head 4–0. Masato Hatanaka claimed a first win over Tasuku Iwami in five meetings, narrowing the head-to-head to 4–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2009-06-29 | Japan F7 | R32 | clay | Tasuku Iwami | 7-5 4-6 6-4 |
| 2009-03-16 | Japan F1 | R32 | hard | Tasuku Iwami | 6-1 6-1 |
| 2008-10-20 | Japan F11 | R16 | hard | Tasuku Iwami | 6-1 6-1 |
| 2001-09-10 | Japan F6 | R32 | hard | Tasuku Iwami | 6-4 6-3 |