Mauricio Estivariz defeated Guillermo Bujniewicz 6-2 6-3 in the Bolivia F1 round of 32 on clay. The upset overturned the form book — Guillermo Bujniewicz came in leading the head-to-head 3–0. Mauricio Estivariz claimed a first win over Guillermo Bujniewicz in four meetings, narrowing the head-to-head to 3–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2009-09-28 | Argentina F17 | R32 | clay | Guillermo Bujniewicz | 6-4 6-4 |
| 2007-08-27 | Argentina F14 | R32 | clay | Guillermo Bujniewicz | 7-6(3) 6-0 |
| 2007-04-23 | Argentina F1 | R32 | clay | Guillermo Bujniewicz | 6-2 6-7(4) 7-6(2) |