Yasufumi Yamamoto defeated Yoshinobu Tanaka 7-6 6-4 in the Japan F4 round of 32 on hard. The upset overturned the form book — Yoshinobu Tanaka came in leading the head-to-head 1–0. Yasufumi Yamamoto claimed a first win over Yoshinobu Tanaka in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1998-11-25 | Japan F6 | R32 | hard | Yoshinobu Tanaka | 6-1 6-1 |