American Kristie Ahn, a lucky loser from qualifying, pulled off a stunning comeback Tuesday to upset top-seeded Jelena Ostapenko of Latvia in the first round of the Claro Open Colsanitas in Bogota, Colombia.
Ahn saved two match points late in the third set and emerged with a 2-6, 7-6 (5), 7-5 win.
Ahn, a 26-year-old New Jersey native who is ranked 205th in the world, needed four match points in the last game to seal the win.
Seventh-seeded Sara Sorribes Tormo of Spain topped Christina McHale 6-4, 6-4, and eighth-seeded Magda Linette of Poland advanced to the second round with a 2-6, 7-6, 6-0 victory over Aliona Bolsova of Spain.
Samsung Open
German qualifier Antonia Lottner upset top seed Belinda Bencic 7-5, 6-2 in Lugano, Switzerland.
Bencic, the world's No. 20 player, couldn't close out her service games and was broken five times by Lottner, ranked No. 182.
The Swiss wasn't the only top seed to fall. Polona Hercog of Slovenia came from one set back to defeat second-seeded Carla Suarez Navarro of Spain 3-6, 6-3, 6-4.
Third-seeded Viktoria Kuzmova of Slovakia is the top seed remaining in the tournament after beating Italian qualifier Giulia Gatto-Monticone 6-2, 6-2.
--Field Level Media
