Atsuo Ogawa defeated Tetsuya Chaen 7-5 7-6 in the Indonesia F2 qualifying round on hard. The upset overturned the form book — Tetsuya Chaen came in leading the head-to-head 5–0, but Atsuo Ogawa had been the form player, winning 2 of their last 6 on hard. Atsuo Ogawa claimed a first win over Tetsuya Chaen in six meetings, narrowing the head-to-head to 5–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2006-04-17 | Japan F2 | R16 | carpet | Tetsuya Chaen | 6-4 6-0 |
| 2005-09-05 | Japan F10 | R32 | hard | Tetsuya Chaen | 6-0 6-1 |
| 2005-08-15 | Indonesia F3 | R16 | hard | Tetsuya Chaen | 6-1 6-2 |
| 2002-04-08 | Japan F1 | R32 | clay | Tetsuya Chaen | 6-2 6-2 |
| 2000-09-18 | Japan F7 | R32 | hard | Tetsuya Chaen | 6-2 6-2 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.