Gustavo Diaz defeated Federico Dondo 6-1 7-5 in the Argentina B Masters 3 round of 32 on clay. The upset overturned the form book — Federico Dondo came in leading the head-to-head 1–0. Gustavo Diaz claimed a first win over Federico Dondo in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1994-08-13 | Argentina 3 Masters 1 | R32 | clay | Federico Dondo | 6-1 6-1 |