Oliver Marach defeated Miha Gregorc 6-2 6-4 in the Mexico F1 round of 16 on hard. The upset overturned the form book — Miha Gregorc came in leading the head-to-head 1–0. Oliver Marach claimed a first win over Miha Gregorc in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1999-11-08 | USA F18 | R16 | hard | Miha Gregorc | 7-6 6-2 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.