The fifth-seeded Acasuso was a 6-4, 6-3 winner over Fabio Fognini, setting up a quarterfinal meeting with Oscar Hernandez.
Acasuso did not play in the Australian Open, but he reached the finals of the Movistar Open and semifinals of the Brazil Open. His win over Fognini boosted his match record this year to 8-2.
Hernandez reached the quarterfinals with a 3-6, 7-6 (7-5), 6-0 victory over Diego Junqueira.
Maximo Gonzalez and Juan Monaco also moved into the quarterfinals. Gonzalez defeated Brian Dabul 6-3, 6-1 and Monaco outlasted Martin Vassallo Arguello 6-4, 2-6, 6-2.