"I think it was a great match," said Korda. "I think I served pretty well. I didn't have too many pressure situations on my serve, and that opens up the returns.
"I think I played a great tie-breaker, and then after that, I just started feeling the ball a little bit better, returning a little better and put some pressure on him."
Korda didn't face a break point as he produced a strong service performance that included a dozen aces.
He will play in the Delray Beach final for the second time, having finished runner-up to Hubert Hurkacz in 2021.
This time he will be up against fifth-seeded fellow American Paul, who rallied to beat fourth-seeded compatriot Learner Tien 4-6, 6-4, 6-3.
Paul is in his first final since he lifted the trophy in Stockholm in 2024. He had been 0-5 in semi-finals since then.
"He obviously was playing amazing tennis in the first (set)," said Paul, who was hindered last season by injuries including a ruptured foot ligament and an abdominal strain.
"I felt like I was really struggling to stay with him. I felt like he was doing everything a little bit better than me. I knew I had to mix things up and try to change the rhythm... I thought I did a great job mixing it up."