Yaoki Ishii defeated Peerakiat Siriluethaiwattana 7-5 6-1 in the Japan F6 round of 16 on carpet. The upset overturned the form book — Peerakiat Siriluethaiwattana came in leading the head-to-head 1–0. Yaoki Ishii claimed a first win over Peerakiat Siriluethaiwattana in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2009-08-17 | Thailand F1 | R16 | hard | Peerakiat Siriluethaiwattana | 7-5 6-3 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.