Jaime Yzaga defeated Stefan Edberg 6-4 7-5 in the Hamburg round of 32 on clay. The upset overturned the form book — Stefan Edberg came in leading the head-to-head 1–0, defending last year's round of 16. Jaime Yzaga claimed a first win over Stefan Edberg in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1991-01-14 | Australian Open | QF | hard | Stefan Edberg | 6-2 6-3 6-2 |