Sergio Cortes defeated Harald Rittersbacher 6-4 6-1 in the Germany 3 Masters 2 round of 16 on clay. The result followed the form book — Sergio Cortes came in leading the head-to-head 1–0. Sergio Cortes extended the head-to-head to 2–0.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1991-05-27 | Germany 3 Masters 4 | QF | clay | Sergio Cortes | 6-2 6-2 |