Top-seeded Pereira knocked out in Rio

Rio de Janeiro - Top-seeded Teliana Pereira of Brazil has been knocked out in the first round of the Rio Open as Petra Martic of Croatia advanced 6-3, 7-5.

Pereira's early loss is a blow for the women's side of the combined WTA-ATP event on outdoor clay. She is only ranked No. 43 but gave local organizers a hometown favourite.

In another early match Tuesday, second-seeded Johanna Larsson of Sweden defeated Lourdes Dominguez Lino of Spain 7-5, 6-4.

In the men's event, Federico Delbonis of Argentina defeated No. 6 seed Jack Sock 7-5, 6-1.

Rafael Nadal is seeded No. 1 followed by fellow Spaniard David Ferrer and Jo-Wilfried Tsonga of France.