Rafael Serpa Guinazu defeated Matias Oneille 6-4 6-4 in the Argentina 2 qualifying round on clay. The upset overturned the form book — Matias Oneille came in leading the head-to-head 2–0. Rafael Serpa Guinazu claimed a first win over Matias Oneille in three meetings, narrowing the head-to-head to 2–1.
Serpa Guinazu R. took it in straight sets.
Rafael Serpa Guinazu beat Matias Oneille 6-4 6-4. Umpiry, "Rafael Serpa Guinazu vs Matias Oneille — Argentina 2 Qualifying Round", https://umpiry.com/match/2000-06-12/guinazu-vs-oneille-argentina-2-qf?utm_source=cite (as of 12 June 2000).