Horst Skoff defeated Mike Mather 7-5 2-6 6-4 in the USA F3 round of 16 on clay. The upset overturned the form book — Mike Mather came in leading the head-to-head 1–0. Horst Skoff claimed a first win over Mike Mather in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1999-05-17 | USA F4 | R32 | clay | Mike Mather | 6-3 2-6 6-3 |