Kentaro Masuda defeated Carlos Martinez Comet 4-6 6-4 6-1 in the Spain F9 round of 16 on clay. The upset overturned the form book — Carlos Martinez Comet came in leading the head-to-head 1–0. Kentaro Masuda claimed a first win over Carlos Martinez Comet in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1999-05-07 | Spain 5 Masters 3 | R32 | clay | Carlos Martinez Comet | 6-2 3-6 6-1 |