Winston-Salem - John Isner ousted top-seeded Jo-Wilfried Tsonga of France 6-4, 3-6, 7-6 (7/3) Friday to stay on track to retain his Winston-Salem ATP title.
Isner, seeded third in the US Open tune-up event, will face second-seeded Czech Tomas Berdych in Saturday's final.
Berdych defeated seventh-seeded American Sam Querrey 6-4, 6-3 in the semi-finals on Friday.
"I'm very, very happy to be back in the final," said Isner, who prefers one more day of tournament action to an early arrival on the practice courts of Flushing Meadows, where the US Open begins on Monday.
"I don't like getting to Grand Slams early. If I'm playing the week before, I want to do as well as I can. I'm playing the final match, so I'm very satisfied with that. I'm looking to defend my title. I did it this year in Newport, so maybe I can pull it off again."
Isner broke Tsonga once to take the opening set and the Frenchman broke Isner once to win the second frame and level the match.
Serving at 5-6 in the deciding third set Tsonga saved two match points - the first with an ace up the middle - but finally couldn't withstand the towering American, who belted 24 aces and wrapped up the victory in two hours and 13 minutes.
Berdych, who accepted a late wild card entry into the tournament, broke Querrey five times en route to victory in one hour and 39 minutes.
Querrey delivered 18 aces but also had five double faults.
"I don't think I necessarily needed to break him five times, but on the other hand, I lost my serve a couple of times. I was trying to get my chances," said Berdych, who is seeking a second title of 2012 after a victory in Montpellier.
In all the match featured eight breaks of serve. Berdych, ranked seventh in the world, had 18 break point chances against the big-serving American.
"It is unusual," Berdych said. "I can play with someone that is not serving as well as Sam and some of the other guys, and I'm struggling to break them for two, three sets, maybe he has service with more slice, spin. But somehow you play with a player and you have a feeling and you know a little bit how to read his serve and it just makes it all of a sudden much more easier."
Querrey said his service mistakes were too costly.
"I played some decent return games," Querrey said. "I broke him a few times. But on my service games, I was throwing in double faults, a couple of easy forehands, and just giving him too many easy breaks on my game points. That makes it tough. I just kind of gave it to him."
Berdych said the outcome of the final will depend largely on how he handles Isner's big serve.
"It's definitely going to be the key to the match, the decider for sure," Berdych said. "He's playing at home, he wants to win as bad as me, so we'll see. It should be a close match."
Results on Friday from the fifth day of the ATP Winston-Salem Open (x denotes seed):
John Isner (USA x3) bt Jo-Wilfried Tsonga (FRA x1) 6-4, 3-6, 7-6 (7/3)
Tomas Berdych (CZE x2) bt Sam Querrey (USA x7) 6-4, 6-3