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.

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 top seed Mardy Fish in today's final. Fish beat Ryan Harrison 6-2, 6-4.

Fish, No. 9 in the world, beat Isner in the 2010 Atlanta final and has not lost a set this week. Isner can improve his No. 35 ranking by beating Fish.

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 or five months," Isner said. "Now that I've got it, I don't want to let it go."

Isner's attempt for back-to-back wins resembles Fish's climb last year. Fish had never won two straight tournaments before winning in Newport and Atlanta.

"I came in on a roll," Fish said. "I had never won two tournaments in a row last year. I felt like I was a different player than in years past and had yet to prove it. That was sort of the start of my run to the top 10."

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.

Harrison, 19, was the first American teen to play in an ATP World Cup semifinal since Sam Querrey lost to Russia's Dmitry Tursunov in July, 2007 in Indianapolis.

By playing in the semifinal, Harrison will become the first American teen since Querrey to be ranked in the top 100. Harrison from Shreveport, La., began the tournament at No. 120.

Australia's Bernard Torric, who is 18 and ranked 73rd, is the only other teen in the top 100.

German Open

At Hamburg, Germany, Gilles Simon of France rallied to beat Mikhail Youznhy of Russia 3-6, 6-3, 6-1 to set up a German Open final against Nicolas Almagro.

Almagro defeated fellow Spaniard Fernando Verdasco 6-4, 6-1.

The fifth-seeded Simon will be looking for his second title of the year in today's final against the third-seeded Almagro. The two have split their previous two matches, but Almagro won the one on clay.

Simon, who won in Sydney in January, lost his first seven matches against Youzhny but has now beaten him twice this year.

Simon served six aces and saved 10 of 13 break points against the fourth-seeded Russian.

Almagro fired seven aces against none for Verdasco and won 83 percent of his first service points.

Almagro is looking for his fourth title of the year.