Isner will face Israel’s Dudi Sela, a 6-3, 3-6, 6-3 winner over Germany’s Ben Becker in a night match.
Isner, ranked No. 12 in the world, improved to 15-3 in the event after saving his best for the end of each set. The former Georgia star broke Sock’s service twice — each time to capture a set.
“I’ve made four finals here. Winston-Salem is my hometown. This feels like my hometown because I went to school here,” Isner said. “I feel like it’s my time of year to play well, and start picking up the pace a little bit.”
Before the final game of the first set, Isner won only two points against Sock’s first five service games.
Then, in a game that lasted 14 minutes and reached deuce nine times, Isner won 13 points and took the set when Sock sent a backhand wide. That was Sock’s third backhand of the set. All three were unforced errors.
“I wasn’t putting any pressure on him, but I told myself that might work to my favor (to crank up his energy),” Isner said. “If I could put a little pressure on him, maybe he could crack a little bit and … second set, same thing.”
Serving at 4-5 in the second set, Sock — who three weeks ago teamed with Canadian Vasek Pospisil to win the doubles title at Wimbledon — double faulted twice.
When Sock sent his last forehand into the net, Isner moved through to the Atlanta final yet again. He lost in there in 2010 and 2011 to Mardy Fish, and fell in the 2012 semifinals to eventual champion Andy Roddick.
As Isner began timing Sock’s first serves better, Sock took off some pace. That may have worked against him.
“It’s disappointing,” Sock said. “Against John, you don’t have many chances at all. I had a good look at a backhand pass … I think it was a combination (in that game) of me missing first serves, and him moving in a few feet closer (to return). “Usually, when he gets his racket on it, he hits it pretty clean. I started missing first serves, and he’s dangerous on the second.”
Sock is ranked 72nd, but will become the second-highest ranked American when the new rankings come out Monday — moving ahead of Sam Querrey (61) and Steve Johnson (64). Querrey won a first-round match over Johnson in Atlanta before falling in the second round.
Pospisil and Sock played Nicolas Barrientos and Victor Estrella Burgos in a doubles semifinal Saturday night for the right to face Querrey and Johnson in the final.