RIO DE JANEIRO (AP) World number three Marin Cilic of Croatia won his debut at the Rio Open. The tournament's top seed beat Argentinian Carlos Berlocq 6-3, 6-2 on Monday.
Fourth seed Albert Ramos Vinolas of Spain overcame Brazilian Rogerio Dutra Silva in three sets: 6-3, 3-6 and 6-4.
Spaniard Fernando Verdasco also needed three sets to win. He qualified to the ATP 500 round of 16 with a 6-2, 3-6 and 6-3 victory over Argentina's Leonardo Mayer.
Second seed and world number six Dominic Thiem of Austria will debut on Tuesday in the clay tournament at Rio de Janeiro's Jockey Club.
On Sunday Thiem won the title of the ATP 250 Argentina Open in Buenos Aires for the second time in the tournament that kicks off Latin America's tennis season.