Luben Pampoulov defeated Ronald Dueller 2-6 6-3 6-2 in the Slovak Republic Masters 3 round of 16 on clay. The upset overturned the form book — Ronald Dueller came in leading the head-to-head 1–0. Luben Pampoulov claimed a first win over Ronald Dueller in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1999-07-26 | Egypt F1 | R16 | clay | Ronald Dueller | 3-6 6-4 7-6 |