Alejandro Fabbri defeated Matias Oneille 5-7 6-3 7-5 in the Guatemala F1 qualifying round on hard. The upset overturned the form book — Matias Oneille came in leading the head-to-head 1–0. Alejandro Fabbri claimed a first win over Matias Oneille in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2003-08-18 | Argentina F1 | QF | clay | Matias Oneille | 6-4 6-4 |