Arata Onozawa defeated Yaoki Ishii 6-4 6-2 in the Japan F4 round of 16 on clay. The upset overturned the form book — Yaoki Ishii came in leading the head-to-head 2–0. Arata Onozawa claimed a first win over Yaoki Ishii in three meetings, narrowing the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2010-06-21 | Japan F7 | R32 | carpet | Yaoki Ishii | 6-3 2-6 7-5 |
| 2010-06-14 | Japan F6 | R16 | carpet | Yaoki Ishii | 6-7(4) 7-6(2) 6-0 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.