Venus Williams beat Garbine Muguruza of Spain in three sets to reach the quarter-finals of the Brazil Tennis Cup on Wednesday.

Williams converted on her fourth match point to beat the 96th-ranked Muguruza 6-4 2-6 7-5 in two-and-a-quarter hours on hardcourt at the southern Brazilian city of Florianopolis.

The American had squandered three match points at 5-4 after getting back on serve late in the third set, but finally closed out the match with her first break point of the final game.

The 20th-ranked Williams is the top-seeded player in Brazil. She is playing her first tournament since losing to Maria Sharapova in the third round of the Australian Open in January.

She will play fifth-seeded Slovakian Magdalena Rybarikova, who defeated qualifier Beatriz Garcia Vidagany of Spain 6-4 3-6 6-4. The 52nd-ranked Rybarikova saved 13 of the 21 break opportunities she conceded in the match that lasted two-and-a-half hours.

Earlier on Wednesday, Timea Babos of Hungary beat fourth-seeded Chanelle Scheepers of South Africa 6-1 6-2.

Babos will play Romania’s Monica Niculescu, who easily downed Tereza Mrdeza of Croatia 6-1 6-1.

Olga Puchkova of Russia continued her remarkable run with a 3-6 6-3 6-3 win over Caroline Garcia of France. Puchkova upset third-seeded Kirsten Flipkens of Belgium in the first round.

Puchkova will play her quarter-final against Slovakia’s Jana Cepelova, who defeated eighth-seeded Annika Beck of Germany 7-6 (8-6) 6-4.

Melinda Czink of Hungary, who eliminated second-seed and 34th-ranked Yaroslava Shvedova of Kazakhstan in the first round, beat Brazilian Bia Haddad Maia 1-6 6-2 7-6 (7-3) to set up a quarter-final against Frenchwoman Kristina Mladenovic, who cruised past Tatjana Malek of Germany 6-2 6-1.