Naoki Tajima defeated Toshihide Matsui 6-3 6-3 in the M25 Urayasu qualifying round of 32 on hard. The upset overturned the form book — Toshihide Matsui came in leading the head-to-head 1–0. Naoki Tajima claimed a first win over Toshihide Matsui in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2017-04-03 | Japan F5 | R32 | hard | Toshihide Matsui | 1-6 6-4 6-3 |