HALLE, Germany -- Top-seeded Roger Federer came from behind to beat defending champion Tommy Haas 3-6, 6-3, 6-4 and reach the Gerry Weber Open final on Saturday.
Federer lost last year's final to the German veteran but he is on course for his first title -- in his second final -- of the year. Federer will play Mikhail Youzhny in Sunday's final. Youzhny upset second-seeded Richard Gasquet 6-3, 6-2 in less than hour.
"It's a good win for me, especially after losing the first set," Federer said. "I felt I played well from start to finish, even in the first set."
Federer is seeking his sixth title on grass in Halle, his favourite warm-up for Wimbledon. Four of Federer's seven Wimbledon titles have come after triumphs in Halle.
While Federer fired 15 aces, Haas finished with nine double-faults. Two consecutive ones at the end of the third game of the final set gave Federer the decisive edge.
"This was my best serving by far this week," Federer said.
Youzhny broke serve for a 2-0 lead and never looked behind. Ha raced to 4-0 in the second and wrapped it with a volley winner. Youzhny is seeking to become the first Russian winner in Halle since Yevgeny Kafelnikov's last of three titles in 2002, the year before Federer began his run of five.
Federer has beaten Youzhny in all of their previous 14 matches, including the semifinals in Halle and the quarterfinals of Wimbledon last year.
"A new match is like a new life, and you never know," Youzhny said.
Although he owns five titles in Halle, where a street going past the stadium is called the Roger-Federer-Allee, the 31-year-old Swiss last won here in 2008.
"It's a big final for me, after that I'll start thinking about Wimbledon," Federer said.
Federer, ranked No. 3 in the world, will be the defending champion in Wimbledon and seeking to add to his record 17 Grand Slam titles.
Federer dropped his serve in the sixth game, hitting a forehand error after being passed by Haas on the previous point.
"Clearly, I wasn't sure how well I was really playing until today," said Federer, who blanked Mischa Zverev 6-0, 6-0 in Friday's quarterfinal and had not been challenged at the tournament.
"When you are a set down, one break and that could be the end for you. Fortunately, I was able to turn it around."
Haas lost his first service game of the second set and would never earn a break point again on Federer's serve.
"On the big points, Roger showed again what qualities he has," Haas said. "I think I still played well and gave my best."
Haas is 3-11 against Federer throughout his career.
The semifinal featured two men over 30. The 35-year-old Haas, the oldest player in the top 100, is enjoying his second spring and is ranked No. 11.
Haas was No. 2 in the world in 2002. Hip surgery in 2010 left him No. 896, before he started climbing again. Unlike Federer, he already has a title this year, in Munich.