Fourth-seeded Tommy Paul out-lasted second-seeded Frances Tiafoe 7-5, 4-6, 7-6 (9/7) on Saturday to book a title clash with Roman Burruchaga at the ATP clay court tournament in Houston, Texas.
Paul improved to 4-1 against fellow American Tiafoe, denying the 2023 champion a fourth straight appearance in the Houston final.
"I did a good job of playing when I needed to," Paul said after prevailing in a match halted by rain in the second set. "That was an incredible match with Big Foe.
Paul, ranked 21st in the world, is into his second final of the year after a runner-up finish to Sebastian Korda at Delray Beach in February.
But the 28-year-old is through to his first clay court final, where in Burruchaga he'll face an opponent playing his first title match.
Burruchaga, ranked 77th, overpowered friend and fellow Argentinian Thiago Tirante 6-1, 6-1.
He seized control with a break in the opening game and never let up, breaking Tirante five times while never facing a break point himself in the 61-minute match.
Tirante, coming off a quarterfinal upset of top-seeded American Ben Shelton, wilted in the face of Burruchaga's relentless pressure.
"We are very close friends, so it is never easy," said Burruchaga, the son of footballer Jorge Burruchaga who famously scored the winning goal for Argentina in the 1986 World Cup final.
"It was a very tough match, so I am happy."