Louis Vosloo defeated Pieter Joubert 6-4 7-5 in the South Africa Masters 4 qualifying round on hard. The upset overturned the form book — Pieter Joubert came in leading the head-to-head 1–0, but Louis Vosloo had been the form player, winning 4 of their last 8 on hard. Louis Vosloo claimed a first win over Pieter Joubert in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1998-10-17 | Central Africa Masters 3 | QF | hard | Pieter Joubert | 7-5 6-1 |