Masaki Sasai defeated Takuto Niki 6-2 6-2 in the Japan F1 round of 32 on hard. The upset overturned the form book — Takuto Niki came in leading the head-to-head 5–1. Masaki Sasai narrowed the head-to-head to 5–2.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2015-06-08 | Japan F6 | QF | hard | Takuto Niki | 6-2 6-1 |
| 2015-03-16 | Japan F2 | QF | hard | Takuto Niki | 7-5 6-3 |
| 2015-03-09 | Japan F1 | R16 | hard | Takuto Niki | 6-2 6-1 |
| 2014-06-23 | Japan F8 | R32 | clay | Masaki Sasai | 6-3 6-1 |
| 2014-06-02 | Japan F5 | R32 | clay | Takuto Niki | 6-4 6-4 |
| 2012-03-19 | Japan F2 | R16 | hard | Takuto Niki | 4-6 6-4 6-4 |
Averages over each player's completed matches in the selected window (12 vs 200). 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