Michihisa Onoda defeated Takahiro Terachi 3-6 6-3 6-1 in the Korea Rep F1 round of 16 on hard. The upset overturned the form book — Takahiro Terachi came in leading the head-to-head 4–0, but Michihisa Onoda had been the form player, winning 5 of their last 7 on hard. Michihisa Onoda claimed a first win over Takahiro Terachi in five meetings, narrowing the head-to-head to 4–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2004-04-19 | Japan F2 | QF | carpet | Takahiro Terachi | 6-3 6-7(0) 6-3 |
| 2002-09-09 | Japan F7 | QF | hard | Takahiro Terachi | 7-6(5) 7-6(2) |
| 1999-05-12 | Japan F3 | SF | hard | Takahiro Terachi | 6-3 4-6 6-3 |
| 1998-10-07 | Japan F4 | QF | carpet | Takahiro Terachi | 7-5 6-3 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.