Bumpei Sato defeated Keita Koyama 6-1 6-1 in the Japan F6 round of 16 on grass. The upset overturned the form book — Keita Koyama came in leading the head-to-head 1–0. Bumpei Sato claimed a first win over Keita Koyama in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2014-06-02 | Japan F5 | QF | clay | Keita Koyama | 2-6 6-4 6-4 |
Averages over each player's completed matches in the selected window (2 vs 1). 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. Small sample — read as indicative. About