Markus Naewie defeated David Prinosil 6-3 3-6 6-3 in the Germany 1 Masters 3 round of 16 on carpet. The upset overturned the form book — David Prinosil came in leading the head-to-head 2–0. Markus Naewie claimed a first win over David Prinosil in three meetings, narrowing the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1991-04-14 | Germany 2 Masters 1 | R16 | clay | David Prinosil | 2-6 7-6 6-0 |
| 1991-03-04 | Spain 3 Masters 1 | R16 | clay | David Prinosil | 6-4 6-2 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.