Mike Mather defeated Donavan September 6-2 6-2 in the USA 3 Masters 2 round of 32 on hard. The upset overturned the form book — Donavan September came in leading the head-to-head 1–0, but Mike Mather had been the form player, winning 5 of their last 8 on hard. Mike Mather claimed a first win over Donavan September in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1998-09-11 | USA 3 Masters 1 | R64 | hard | Donavan September | 6-2 6-1 |