(Photo credit: Geoff Burke-Imagn Images)

Top-seeded and World No. 27 Beatriz Haddad Maia had trouble getting to the finish line, but did knock off Laura Pigossi, 6-1, 6-4, in a battle of Brazilians at the Sao Paulo Open on Thursday.

Haddad Maia, who reached the fourth round of the U.S. Open, breezed through the first set in 36 minutes and took a 5-1 lead in the second set. But the 31-year-old Pigossi proved to be a tough out, holding serve twice and breaking the highest-ranked Brazilian woman in the eighth game. She won two of the first three points in the 10th game, but Haddad Maia won the final three points and captured the second-round match.

Haddad Maia on Friday will take on fifth-seeded Mexican Renata Zarazua, who bested Turkey's Berfu Cengiz 6-4, 6-4. Zarazua defeated Madison Keys in the first round of the U.S. Open.

Hungary's Panna Udvardy defeated another home country favorite, Ana Candiotto, 6-3, 6-3.

Guadalajara Open

The two top seeds, Belgium's Elise Mertens and Russia's Veronika Kudermetova, fell in the afternoon session during second-round play.

The top-seeded Mertens dropped a 4-6, 6-3, 6-4 decision to France's Elsa Jacquemot in a 2-hour, 31-minute thriller, while Andorra's Victoria Jiminez Kasintseva vanquished No. 2 Kudermetova 6-4, 6-2.

Mertens was broken at 15-40 in the first game of the deciding set and lost her serve at love in the fifth game. Jiminez Kasintseva fended off all four of her opponent's break point chances, while capitalizing on 3 of 6.

In the other afternoon match, Colombia's Emiliana Arango defeated Australian Storm Hunter 6-2, 6-2.

No. 3 Jelena Ostapenko of Latvia, the top seed remaining, was scheduled to face Canada's Marina Stakusic in the evening session. Three other second-round matches are on the program.

--Field Level Media