Hiromasa Oku defeated Gengo Kikuchi 6-3 7-6 in the Japan F6 round of 32 on hard. The upset overturned the form book — Gengo Kikuchi came in leading the head-to-head 3–0. Hiromasa Oku claimed a first win over Gengo Kikuchi in four meetings, narrowing the head-to-head to 3–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2016-03-21 | Japan F3 | Q16 | hard | Gengo Kikuchi | 6-2 6-1 |
| 2014-07-14 | Hong Kong F2 | R32 | hard | Gengo Kikuchi | 6-7(3) 6-4 6-2 |
| 2014-05-26 | Guam F1 | R32 | hard | Gengo Kikuchi | 6-4 6-3 |
Averages over each player's completed matches in the selected window (19 vs 57). ATP, WTA & Challenger.
Each player's serve crossed against the other's return, converted to expected hold of serve. Recent completed matches, ATP, WTA & Challenger. About