Matias Oneille defeated Diego Junqueira 3-6 6-1 6-1 in the Paraguay F1 round of 16 on clay. The upset overturned the form book — Diego Junqueira came in leading the head-to-head 2–0, but Matias Oneille had been the form player, winning 4 of their last 9 on clay. Matias Oneille claimed a first win over Diego Junqueira in three meetings, narrowing the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2001-07-30 | Argentina F7 | R16 | clay | Diego Junqueira | 6-1 6-0 |
| 2000-08-14 | Argentina F10 | R16 | clay | Diego Junqueira | 6-4 6-2 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.