Giron to face Paul in ATP Dallas Open final after beating Mannarino
Paul beat fellow American Ben Shelton 6-2, 6-4 to reach Sunday's final, where he'll be chasing a second ATP Tour title as Giron seeks his first.
Giron, ranked 67th in the world, followed up a dominant quarter-final victory over top-seeded Frances Tiafoe with another convincing win.
He saved the only break point he faced, and converted four of his eight break chances against France's Mannarino, the world number 17 who won three titles last year to take his career tally to five.
Giron will be playing in just his second ATP final, having fallen in his first at San Diego in 2022.
Paul, ranked 15th in the world, needed just 79 minutes to eliminate 16th-ranked Shelton.
"These courts helped me a little bit," Paul said. "They're not jumping quite as high as some of the other courts we've played on. Kept the ball in my strike zone a little bit more."
Paul snapped a six-match losing streak against top-20 opponents to reach his fourth career ATP final.
He won his only title to date in Stockholm in 2021, but lost in the finals at Acapulco and Eastbourne last year after a run to his first Grand Slam semi-final at the 2023 Australian Open.
Paul broke for a 3-2 lead and reeled off four games in succession to capture the opening set.
In the second set, Shelton sent a backhand volley wide to surrender a break and give Paul a 2-1 edge. They both held serve from there until the end.