RIO DE JANEIRO — Third-seeded Danka Kovinic of Montenegro and No. 5 Polona Hercog of Slovenia each advanced to the second round of the Rio Open clay-court tournament on Monday.
Kovinic defeated Sachia Vickery of the United States 6-3, 5-7, 6-4, and Hercog also won over an American, beating Jennifer Brady 6-4, 6-2.
The Americans picked up a victory when Shelby Rogers upset No. 8 Andreea Mitu of Romania, 6-2, 6-2.
The combined ATP and WTA tournament was halted by torrential rain for an hour in the early evening without a men's match being completed.
Rafael Nadal is seeded No.