Spanish pair safely through
David Ferrer and Nicolas Almagro remain on course to reprise their 2012 Copa Claro final after both men won their quarter-finals.
Top seed and reigning champion Ferrer made light work of sixth seed Fabio Fognini with a 6-2 6-1 success in Buenos Aires on Friday.
The man he beat into the runner-up spot last year, fellow Spaniard Almagro, lined up against Argentinean wild card Federico Delbonis and recorded a 6-1 7-6(3) victory.
Ferrer's semi-final opponent is another Spaniard, Tommy Robredo, afrer he defeated Julian Reister 6-3 6-2.
Third seed Stanislas Wawrinka is next for Almagro after he prevented a Spanish clean sweep in the last four, seeing off Albert Ramos 7-6(4) 6-4.