On Friday, defending champion Carlos Alcaraz defeated Italian qualifier Andrea Vavassori in straight sets to advance to the Buenos Aires clay-court competition semifinals.
Playing in his first tournament since an unexpected quarterfinal exit at the Australian Open, world number two Alcaraz defeated his opponent 7-6 (7/1), 6-1.
Vavassori, who at the Madrid Masters last year upset three-time major champion Andy Murray on clay, matched the Spanish player blow for blow in the opening set.
But after an hour and forty minutes on the court, Alcaraz stormed to a 5-0 lead in the second set and won.
"In the first set he played such a high level," Alcaraz said.
"It was really tough to return his serve and challenging conditions with the wind. But I think I played better in the second set.
"His level went down a bit, with his serve as well and I put some returns in, took my chances and I think that was the difference."
The 20-year-old Spaniard will face either Chilean third seed Nicolas Jarry or Argentina's Tomas Etcheverry, seeded sixth, for a place in Sunday's title match.