Tetsuya Chaen defeated Hiroki Ishii 6-4 6-4 in the Japan F5 round of 16 on hard. The upset overturned the form book — Hiroki Ishii came in leading the head-to-head 1–0. Tetsuya Chaen claimed a first win over Hiroki Ishii in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2000-03-27 | Japan F3 | R32 | clay | Hiroki Ishii | 2-6 7-6(7) 6-3 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.