Chilean Tomas Barrios Vera: Briton Cameron Norrie made a perfect start to his Rio Open title defence when he defeated Bolivian Hugo Dellien 6-3, 6-2.
The second seed saved the only break point he faced and converted three of his seven opportunities to advance to the second round of the ATP 500 after one hour and 22 minutes on Monday night, ATP reports.
Norrie will next play Chilean Tomas Barrios Vera, who eliminated Brazilian wild card Gustavo Heide 7-5, 6-3.
In other action, fourth seed Francisco Cerundolo snapped a three-match losing streak with a 6-1, 1-6, 6-2 victory against fellow Argentine Francisco Comesana.
The two-time ATP Tour titlist will face Spaniard Albert Ramos-Vinolas in the second round.
The former No. 17 player in the ATP Rankings, Ramos-Vinolas clawed past Peruvian Juan Pablo Varillas 3-6, 6-3, 7-5 after two hours and 44 minutes.