Diego Alvarez defeated Matias Oneille 6-1 5-7 6-4 in the Italy 5 2 round of 32 on clay. The upset overturned the form book — Matias Oneille came in leading the head-to-head 1–0. Diego Alvarez claimed a first win over Matias Oneille in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1999-10-11 | Paraguay F1 | R32 | clay | Matias Oneille | 6-4 2-6 7-6 |