NORCROSS, Ga. — John Isner, in position to win back-to-back tournaments for the first time in his career, is savoring the confidence that has come with his success.

Isner overwhelmed Gilles Muller in the third set to win 7-5, 6-7 (3), 6-1 on Saturday to reach the Atlanta Tennis Championships final for the second straight year.

Isner, the No. 3 seed, will face either top seed Mardy Fish or 19-year-old Ryan Harrison in Sunday's final. Fish beat Isner in the 2010 final.

Coming off a victory in the Hall of Fame Tennis Championships on the grass courts in Newport, R.I., two weeks ago, Isner said his game is soaring with his confidence on Atlanta's hard courts.

"I've been waiting for this feeling for about four of five months," Isner said. "Now that I've got it, I don't want to let it go."

The 6-foot-9 Isner, who is best known for his powerful serves, said he is making good decisions that help him enjoy a more complete game.

"It's as simple as confidence," he said. "I always play my best when I'm confident. I move my best when I'm confident.

"I'm not the fastest guy out there but I feel I've been moving well this week and that comes with having a clear mind and making the right decisions on the court."

In the key game of the match, the 6-foot-9 Isner hit an overhand winner to break Muller's serve for a 2-0 lead in the third set. Muller reacted by slamming his racket to the court, demolishing the racket.

Muller never recovered. Isner broke the left-hander's serve again for a 4-0 lead.

"I thought I made a lot of hard work in the second set to win that set and then right away in the beginning of the third one, I threw all my chances away," Muller said. "It was hard to take."

Isner said he hit "kind of a junk volley" to set up the key overhand winner.

"It took some pressure off, for sure," Isner said.

Isner hit 28 aces, including 11 in the third set. Muller had 16 aces, but only three in the final set. Muller never broke Isner's serve.

It was the second straight year Isner, the former University of Georgia star, beat Muller, from Luxembourg, in three sets in Atlanta.