US teen Alex Michelsen ended Reilly Opelka's comeback from a layoff of nearly two years on Saturday, ousting his countryman to reach the Hall of Fame Open final.
Michelsen, last year's Newport runner-up, defeated Opelka 6-2, 6-0 in only 59 minutes in the ATP grass-court event at Rhode Island.
"At the beginning, he was having break points on my serve and I was like, this is going to be one of those matches that's going to come down to the wire," Michelsen said.
"And then I didn't miss a return when I touched the ball. Probably the best tournament day of my life."
In the other all-American semifinal, Chris Eubanks, who won his only ATP final on Mallorca grass in June 2023, will face second seed Marcos Giron, who lost his only prior ATP finals in 2022 in San Diego and this past February in Dallas.
Michelsen, ranked 61st, became the youngest player since Spain's Carlos Alcaraz at Umag in 2022 to reach consecutive finals at the same ATP event.
"Last year I had zero expectations on myself and this year I put a little bit more expectations on myself," Michelsen said.
"I'm going to be taking a lot more experience into the match. Last year in the final I had about zero and now I've got a year."
Opelka, who sent a backhand wide to end matters, was playing in his first ATP event since 2022 at Washington.
At 1 188th in the world, Opelka is the lowest-ranked player in the ATP era to reach a semifinal, having tumbled down the ATP standings during his absence following hip and wrist operations.
Michelsen lost to France's Adrian Mannarino in last year's final.