Tetsuya Sato defeated Toshitsugu Mori 6-2 6-2 in the Japan Masters 1 round of 16 on hard. The upset overturned the form book — Toshitsugu Mori came in leading the head-to-head 1–0. Tetsuya Sato claimed a first win over Toshitsugu Mori in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1993-11-08 | Japan Masters 3 | R32 | hard | Toshitsugu Mori | 6-3 6-4 |