Marcel Zielinski defeated Simon Beaupain 6-3 6-1 in the M15 Eupen 1 semi-final on clay. The upset overturned the form book — Simon Beaupain came in leading the head-to-head 1–0. Marcel Zielinski claimed a first win over Simon Beaupain in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2023-11-15 | M15 Monastir 46 | R32 | hard | Simon Beaupain | 6-3 6-1 |