Arata Onozawa defeated Masaki Sasai 6-4 6-2 in the Japan F5 round of 32 on clay. The upset overturned the form book — Masaki Sasai came in leading the head-to-head 2–0. Arata Onozawa claimed a first win over Masaki Sasai in three meetings, narrowing the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2017-06-05 | Japan F7 | R32 | hard | Masaki Sasai | 3-6 6-2 6-3 |
| 2015-03-16 | Japan F2 | R32 | hard | Masaki Sasai | 6-4 6-4 |
Averages over each player's completed matches in the selected window (46 vs 12). 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