It's the sixth time Acasuso has reached at least the quarterfinals in the clay event at Buenos Aires Lawn Tennis Club.
Fifth-seeded Acasuso won five straight games to win the first set and go up 3-0 in the second. Taking the match on his fourth match point, Acasuso maintained his strong play this month. He was runner-up in Chile and a semifinalist in Brazil.
Juan Monaco, the 2007 champion of his hometown event, beat another local, Martin Vassallo Arguello, 6-4, 2-6, 6-2 but complained afterward that the match shouldn't have been played in the 104-degree heat.
The players constantly toweled themselves off and both let difficult shots fall to the wayside to conserve energy during a match that lasted 2 hours, 14 minutes.
"It's difficult to play good tennis in such heat," Monaco said. "It's unhealthy and organizers should think more of the players' health. Luckily there are not many tournaments played in such high temperatures."
Monaco will face qualifier Maximo Gonzalez in the latter's first quarterfinals since July.
Coming off a win over two-time champion Carlos Moya, Gonzalez downed Argentine compatriot Brian Dabul 6-3, 6-1.
"In this tournament I have gained a lot of confidence," Gonzalez said.
Oscar Hernandez prevented an Argentina sweep when he beat Diego Junqueira 3-6, 7-6 (5), 6-0. Even so, there are four Argentines in the quarterfinals, and Hernandez, who won his first match of the year in the first round, will meet one in Acasuso.