Jumpei Yamasaki advanced when Takuya Kumasaka retired 1-6 4-5 in the M25 Sapporo 1 round of 16. Jumpei Yamasaki extended the head-to-head to 3–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2025-09-19 | M25 Takasaki 1 | QF | hard | Takuya Kumasaka | 6-7(6) 6-0 6-3 |
| 2023-12-29 | M15 Yanagawa 2 | QF | hard | Jumpei Yamasaki | 6-1 6-4 |
| 2023-06-01 | M15 Karuizawa 1 | R16 | clay | Jumpei Yamasaki | 6-3 6-2 |
Averages over each player's completed matches in the selected window (5 vs 38). ATP, WTA & Challenger.
Kumasaka T.: 5 days rest · 3 matches, 64 games (7d). Higher means fresher. About
Each player's serve crossed against the other's return, converted to expected hold of serve. Recent completed matches, ATP, WTA & Challenger. About