Arata Onozawa defeated Jae Sung An 6-3 6-2 in the Thailand F2 round of 32 on hard. The upset overturned the form book — Jae Sung An came in leading the head-to-head 2–0. Arata Onozawa claimed a first win over Jae Sung An in three meetings, narrowing the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2011-04-11 | Thailand F3 | R16 | hard | Jae Sung An | 6-3 6-2 |
| 2009-07-13 | Korean Rep F5 | R32 | hard | Jae Sung An | 7-5 6-4 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.