John Sperle defeated Marcel Zielinski 6-2 6-1 in the M15 Amstelveen 1 round of 32 on clay. The upset overturned the form book — Marcel Zielinski came in leading the head-to-head 3–0. John Sperle claimed a first win over Marcel Zielinski in four meetings, narrowing the head-to-head to 3–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2024-03-27 | M15 Antalya 8 | R32 | clay | Marcel Zielinski | 7-5 6-4 |
| 2023-04-26 | M15 Meerbusch 1 | R32 | clay | Marcel Zielinski | 7-6(5) 7-5 |
| 2022-08-15 | M15 Eindhoven 1 | Q16 | clay | Marcel Zielinski | 6-2 7-6(3) |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.