Naoki Arimoto defeated Hiroyasu Sato 6-4 6-3 in the Japan F1 round of 32 on carpet. The upset overturned the form book — Hiroyasu Sato came in leading the head-to-head 1–0. Naoki Arimoto claimed a first win over Hiroyasu Sato in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2004-08-30 | Japan F6 | R32 | hard | Hiroyasu Sato | 6-4 7-5 |