The top two seeds Casper Ruud and Diego Schwartzman will face off in the Argentina Open final after the latter won two matches on Saturday to progress at his home event.
The Argentine world number 14 had to overcome countryman Francisco Cerundolo 6-3 2-6 5-7 earlier on Saturday after their quarter-final had been interrupted by rain on Friday evening.
The match was tied at 1-1 in the third set when rain intervened, with Schwartzman triumphing when play resumed to earn a semi-final date with third seed Lorenzo Sonego.
Schwartzman would later beat Sonego 7-5 3-6 6-2 in almost three hours on a busy day for the 2020 French Open semi-finalist.
World number eight Ruud progressed with a routine 6-3 6-3 victory over Argentine sixth seed Federico Delbonis.
At the Dallas Open semi-finals, Reilly Opelka and John Isner broke the record for the longest tiebreaker on the ATP Tour since 1990.
Second seed Opelka triumphed over fellow American Isner but it was not easy, winning 7-6 (9-7) 7-6 (24-22).
Opelka sent down 39-21 aces across the match, earning a spot in the final against fourth seed Jenson Brooksby who beat Marcos Giron 6-4 6-7 (4-7) 7-6 (7-5).