Yaoki Ishii defeated Woong Sun Jun 6-4 7-5 in the Japan F1 round of 16 on hard. The upset overturned the form book — Woong Sun Jun came in leading the head-to-head 1–0, but Yaoki Ishii had been the form player, winning 3 of their last 6 on hard. Yaoki Ishii claimed a first win over Woong Sun Jun in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2006-06-12 | Japan F6 | R16 | clay | Woong Sun Jun | 6-4 6-4 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.