Guillermo Bujniewicz defeated Nicolas Jara Lozano 6-7 6-4 6-4 in the Argentina F6 round of 32 on clay. The upset overturned the form book — Nicolas Jara Lozano came in leading the head-to-head 5–0. Guillermo Bujniewicz claimed a first win over Nicolas Jara Lozano in six meetings, narrowing the head-to-head to 5–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2009-10-19 | Argentina F20 | R16 | clay | Nicolas Jara Lozano | 3-6 6-1 6-0 |
| 2009-09-14 | Argentina F15 | R32 | clay | Nicolas Jara Lozano | 6-4 3-6 6-3 |
| 2009-06-22 | Argentina F10 | R16 | clay | Nicolas Jara Lozano | 3-6 6-3 6-2 |
| 2009-05-11 | Argentina F5 | R16 | clay | Nicolas Jara Lozano | 1-6 6-1 6-2 |
| 2008-11-10 | Argentina F16 | R16 | clay | Nicolas Jara Lozano | 6-2 6-3 |