Kentaro Masuda defeated Toshihide Matsui 6-4 6-3 in the Japan F7 qualifying round on hard. The upset overturned the form book — Toshihide Matsui came in leading the head-to-head 1–0, but Kentaro Masuda had been the form player, winning 3 of their last 10 on hard. Kentaro Masuda claimed a first win over Toshihide Matsui in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2004-03-15 | New Zealand F3 | R32 | hard | Toshihide Matsui | 6-4 3-0 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.