Koichi Sano defeated Arata Onozawa 2-6 6-1 6-0 in the Japan F8 round of 16 on carpet. The upset overturned the form book — Arata Onozawa came in leading the head-to-head 1–0. Koichi Sano claimed a first win over Arata Onozawa in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2016-09-12 | Vietnam F4 | R32 | hard | Arata Onozawa | 2-6 7-6(9) 6-0 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.