Suchanun Viratprasert defeated Seiko Okamoto 6-2 6-1 in the Haibara 10K semi-final on carpet. The result followed the form book — Suchanun Viratprasert came in leading the head-to-head 3–1. Suchanun Viratprasert extended the head-to-head to 4–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2009-08-31 | Tsukuba 25K | R16 | hard | Suchanun Viratprasert | 6-2 6-4 |
| 2008-07-14 | Miyazaki 25K | R32 | carpet | Suchanun Viratprasert | 6-0 7-5 |
| 2004-11-15 | Nuriootpa 25K | R16 | hard | Seiko Okamoto | 6-4 0-6 6-0 |
| 2004-08-02 | Louisville 50K | R32 | hard | Suchanun Viratprasert | 6-1 6-1 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.