Guillermo Bujniewicz defeated Marcos Conocente 7-5 6-3 in the Chile F3 round of 16 on clay. The upset overturned the form book — Marcos Conocente came in leading the head-to-head 2–1. Guillermo Bujniewicz narrowed the head-to-head to 2–2.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2009-05-04 | Argentina F4 | R16 | clay | Marcos Conocente | 6-4 6-2 |
| 2006-09-18 | Bolivia F2 | R32 | clay | Marcos Conocente | 6-4 6-4 |
| 2006-09-11 | Bolivia F1 | R16 | clay | Guillermo Bujniewicz | 7-6(5) 6-2 |