Rudiger Haas defeated Lars Koslowski 6-4 2-6 7-6 in the Germany 1 Masters 3 round of 32 on carpet. The upset overturned the form book — Lars Koslowski came in leading the head-to-head 1–0. Rudiger Haas claimed a first win over Lars Koslowski in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1991-02-03 | Germany 1 Masters 1 | QF | carpet | Lars Koslowski | 6-1 4-6 7-5 |