Issei Okamura defeated Seiya Nakanishi 6-2 6-4 in the M25 Tsukuba 1 qualifying round of 32 on hard. Issei Okamura extended the head-to-head to 3–0.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2025-09-02 | M25 Sapporo 1 | Q16 | hard | Issei Okamura | 4-6 7-6(5) 10-8 |
| 2023-09-05 | M25 Sapporo 1 | R32 | hard | Issei Okamura | 6-1 6-1 |
Averages over each player's completed matches in the selected window (81 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