Ruben Ramirez Hidalgo defeated Carlos Castellanos 6-3 6-0 in the Spain 6 Masters 3 qualifying round on clay. The upset overturned the form book — Carlos Castellanos came in leading the head-to-head 3–0. Ruben Ramirez Hidalgo claimed a first win over Carlos Castellanos in four meetings, narrowing the head-to-head to 3–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1998-07-27 | Spain F4 | R16 | clay | Carlos Castellanos | 6-4 6-2 |
| 1998-06-05 | Spain 6 Masters 4 | R16 | clay | Carlos Castellanos | 6-7 6-1 6-4 |
| 1998-05-08 | Spain 5 Masters 3 | R16 | clay | Carlos Castellanos | 3-6 7-6 6-0 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.