Thomas Gollwitzer defeated Rene Hanak 6-7 6-0 6-1 in the Czechoslovakia Masters 1 round of 32 on clay. The upset overturned the form book — Rene Hanak came in leading the head-to-head 1–0, but Thomas Gollwitzer had been the form player, winning 4 of their last 8 on clay. Thomas Gollwitzer claimed a first win over Rene Hanak in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1991-08-26 | Czechoslovakia Masters 4 | F | clay | Rene Hanak | 6-4 6-2 |