Dimitrije Zubac defeated Shunsuke Wakita 6-1 4-6 10-1 in the M25 Pirot 1 q16 on clay. The upset overturned the form book — Shunsuke Wakita came in leading the head-to-head 1–0. Dimitrije Zubac claimed a first win over Shunsuke Wakita in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2021-09-19 | M15 Pirot 1 | Q64 | clay | Shunsuke Wakita | 7-6(4) 6-2 |