There is guaranteed to be an Argentine winner of the Cordoba Open on Saturday, while Taylor Fritz was stunned in Dallas.
Federico Coria, seeded sixth, overcame reigning champion and 2021 runner-up Albert Ramos-Vinolas 6-4 7-6 (7-2) after over two-and-a-half hours of action.
The world number 67, who is into his second ATP Tour-level final and is set to rise into the top 50 of the rankings, has dropped just a single set in the tournament.
Sebastian Baez, eight years Coria's junior, is aiming for his second title after winning in Estoril last year.
The 22-year-old fourth seed defeated Hugo Dellien 6-4 6-4.
This will be the fourth singles final of Baez's career, though his first on home soil.
"It means a lot, but [it brings] confidence," said Baez.
"I have my people here, my friends, my family, everything, so that is a big motivation for me."
While Coria and Baez have just five previous final appearances between them, John Isner advanced to a 31st Tour-level showdown of his career as he beat fellow American J.J. Wolff at the Dallas Open.
Playing in his home city, 37-year-old Isner came from behind to prevail 3-6 7-5 7-6 (7-4).
Isner offered up eight break points, but saved seven of them to frustrate Wolff.
"I saved a lot of break points with unreturnable serves," Isner said. "Without that I would have been dusted off the court 6-3, 6-4. I'm of course very fortunate to have that weapon in my pocket, and I needed every bit of it today.
"It was an absolute battle, so I'm pretty tired. But I'm absolutely ecstatic to be in the final tomorrow here in Dallas."
Asked how he was faring up after his long tussle with Wolff, Isner quipped: "Truthfully, it feels terrible right now. I'm 38 in April. It's not getting any easier. I started off a little slow, a little sluggish, but in the third set I actually felt the best I felt the whole match.
"I had a lot of adrenaline there at the end and I was able to hold my nerve and win. Right now the name of the game is recovery."
Isner will be the favourite in the final, after top seed Fritz surrendered a lead in a 6-7 (3-7) 7-5 6-4 loss to Wu Yibing.