Roberto Menendez defeated Oscar Martinez Dieguez 6-4 5-7 6-1 in the Spain 4 1 round of 16 on clay. The upset overturned the form book — Oscar Martinez Dieguez came in leading the head-to-head 1–0. Roberto Menendez claimed a first win over Oscar Martinez Dieguez in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1999-05-07 | Spain 5 Masters 3 | F | clay | Oscar Martinez Dieguez | 6-3 2-6 6-4 |