Marin Cilic's Rio Open clash against Gael Monfils was suspended due to rain at a crucial stage, while Albert Ramos-Vinolas made a second-round exit.
With only two of the four scheduled singles matches completed on Wednesday, rain saw the day's play suspended.
The blockbuster clash between top seed Cilic and Frenchman Monfils was stopped in a second-set tie-break.
Monfils took the first set 6-3 and the duo were locked at 7-7 in the tie-break when play was suspended for the day.
Cilic had recovered from a break down in the second set and squandered two set points, while also saving a match point.
Ramos-Vinolas exited in one of two completed matches, losing to Nicolas Jarry 7-5 6-3.
The day's other match saw sixth seed Diego Schwartzman cruise past fellow Argentinian Federico Delbonis 6-2 6-3.