Gustavo Marcaccio defeated Patricio Arquez 6-4 6-1 in the Chile F5 qualifying round on clay. The upset overturned the form book — Patricio Arquez came in leading the head-to-head 2–1, but Gustavo Marcaccio had been the form player, winning 6 of their last 10 on clay. Gustavo Marcaccio narrowed the head-to-head to 2–2.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2000-09-04 | Peru F2 | R16 | clay | Patricio Arquez | 6-2 6-2 |
| 2000-08-14 | Argentina F10 | R16 | clay | Gustavo Marcaccio | 7-6(5) 4-6 6-4 |
| 2000-06-12 | Argentina 1 | QF | clay | Patricio Arquez | 6-3 6-2 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.