Ji Hee Choi defeated Hyun Hui Hong 6-4 3-6 6-2 in the Goyang $25K qualifying round on hard. The upset overturned the form book — Hyun Hui Hong came in leading the head-to-head 3–1. Ji Hee Choi narrowed the head-to-head to 3–2.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2014-05-26 | Changwon 25K | QF | hard | Hyun Hui Hong | 6-2 4-6 7-5 |
| 2012-05-21 | Changwon 25K | R32 | hard | Hyun Hui Hong | 6-0 7-6(6) |
| 2011-05-30 | Gimcheon 25K | Q32 | hard | Hyun Hui Hong | 6-3 6-1 |
| 2011-04-11 | Incheon 25K | Q32 | hard | Ji Hee Choi | 6-2 6-0 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.