Marcel Zimmermann defeated Marc Sieber 7-6 0-6 6-3 in the Croatia F4 round of 16 on clay. Marcel Zimmermann extended the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2011-04-04 | Croatia F5 | R16 | clay | Marc Sieber | 6-1 2-0 |
| 2007-04-02 | Turkey F1 | R32 | clay | Marcel Zimmermann | 6-1 6-3 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.