Ana Clara Duarte defeated Tatiana Bua 6-3 5-7 6-4 in the Buenos Aires 10K semi-final on clay. The upset overturned the form book — Tatiana Bua came in leading the head-to-head 2–0, but Ana Clara Duarte had been the form player, winning 3 of their last 4 on clay. Ana Clara Duarte claimed a first win over Tatiana Bua in three meetings, narrowing the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2009-11-09 | Itajai 10K | F | clay | Tatiana Bua | 6-1 7-5 |
| 2008-04-14 | Mazatlan 10K | R16 | hard | Tatiana Bua | 6-3 4-6 6-4 |