Daniel Navas defeated Carlos Castellanos 6-1 6-4 in the Spain 6 Masters 4 qualifying round on clay. The upset overturned the form book — Carlos Castellanos came in leading the head-to-head 1–0. Daniel Navas claimed a first win over Carlos Castellanos in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1998-07-20 | Spain F3 | R32 | clay | Carlos Castellanos | 7-5 6-2 |