Masato Shiga defeated Keisuke Watanuki 7-6 6-4 in the Japan F2 round of 32 on hard. The upset overturned the form book — Keisuke Watanuki came in leading the head-to-head 2–0. Masato Shiga claimed a first win over Keisuke Watanuki in three meetings, narrowing the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2016-03-21 | Japan F3 | Q16 | hard | Keisuke Watanuki | 6-4 2-6 6-3 |
| 2014-06-23 | Japan F8 | R32 | clay | Keisuke Watanuki | 6-4 6-2 |
Averages over each player's completed matches in the selected window (59 vs 11). 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