RIO DE JANEIRO -- Defending champion Diego Schwartzman retired from the Rio Open on Wednesday because of a right leg injury.
The fourth-seeded Argentine athlete trailed Uruguay's Pablo Cuevas 6-1, 4-1 before stopping play. The first-round match began Tuesday and was interrupted by rain.
Cuevas, the 2016 winner, will face Argentina's Juan Ignacio Londero in the round of 16.
In second-round matches, Jaume Munar of Spain beat Cameron Norrie of Britain 7-6 (6), 5-7, 7-6 (4); Bolivia's Hugo Dellien topped Roberto Carballes Baena of Spain 7-5, 6-4; and Slovenia's Aljaz Bedene beat Thiago Monteiro of Brazil 6-3, 6-4.