Cecilia Costa Melgar defeated Barbara Rush 6-3 5-7 6-3 in the Buenos Aires 10K round of 32 on clay. The upset overturned the form book — Barbara Rush came in leading the head-to-head 2–0. Cecilia Costa Melgar claimed a first win over Barbara Rush in three meetings, narrowing the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2011-03-21 | Rancagua 10K | R32 | clay | Barbara Rush | 4-6 7-6(3) 6-4 |
| 2009-11-30 | La Serena 10K | QF | clay | Barbara Rush | 7-5 6-3 |