Masashi Tokumaru defeated Yasufumi Yamamoto 6-1 3-6 6-1 in the Japan 2 Masters 4 round of 32 on hard. The upset overturned the form book — Yasufumi Yamamoto came in leading the head-to-head 1–0. Masashi Tokumaru claimed a first win over Yasufumi Yamamoto in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1999-03-17 | Japan F1 | R16 | clay | Yasufumi Yamamoto | 6-3 6-2 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.