Bumpei Sato defeated Arata Onozawa 6-3 6-3 in the Japan F5 round of 32 on clay. The upset overturned the form book — Arata Onozawa came in leading the head-to-head 4–0. Bumpei Sato claimed a first win over Arata Onozawa in five meetings, narrowing the head-to-head to 4–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2011-06-27 | Japan F8 | R16 | clay | Arata Onozawa | 6-4 2-6 6-1 |
| 2011-06-06 | Japan F5 | QF | clay | Arata Onozawa | 7-5 6-4 |
| 2010-07-26 | USA F20 | R16 | hard | Arata Onozawa | 6-1 6-3 |
| 2010-04-05 | Japan F4 | QF | hard | Arata Onozawa | 6-1 6-4 |
Averages over each player's completed matches in the selected window (2 vs 46). 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