Ferrer into semis in Argentina
The world number five took the opening set comfortably before breaking in the ninth game of the second and serving out to seal victory.
"It was a difficult match," Ferrer said. "Fernando is a great player, one of the greatest in history. And as a person he is even better."
Gonzalez. 31, will retire after next month's tournament in Florida and was reflective after the defeat.
"The last tournament ... I’m glad I’ll have time to recover after all the running that David made me do," he said.
Almagro, who won the Brazil Open last week, beat Igor Andreev in straight sets 6-3 7-5 to book his place in the last four.
"I’m happy after having beaten a great player like Igor," Almagro said. "The second set was very tough."
Swiss Wawrinka progressed after 6-4 6-2 victory over Japanese fourth seed Kei Nishikori.