Matias Oneille defeated Federico Dondo 6-0 7-6 in the Uruguay F1 round of 16 on clay. The upset overturned the form book — Federico Dondo came in leading the head-to-head 1–0, but Matias Oneille had been the form player, winning 5 of their last 10 on clay. Matias Oneille claimed a first win over Federico Dondo in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1998-12-07 | Uruguay F3 | R32 | clay | Federico Dondo | 6-2 6-1 |