HALLE, Germany -- In a match featuring two men over 30, Roger Federer rallied past defending champion Tommy Haas 3-6, 6-3, 6-4 Saturday to reach the final of the Gerry Weber Open.

Federer lost last year's final to the German veteran. But he's on course for his first title -- in his second final -- of the year.  
Federer will play Mikhail Youzhny in the final on Sunday. 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."  
The semifinal featured the 35-year-old Haas, the oldest player in the top 100, and 31-year-old Federer. The 11th-ranked Haas, who reached the quarterfinals of the French Open, is enjoying a resurgence after various injuries.  
Federer is seeking his sixth title on grass in Halle, his favorite warm-up for Wimbledon. Four of Federer's seven Wimbledon titles have come after wins in Halle.  
Federer had 15 aces and Haas finished with nine double-faults. Consecutive double-faults by Haas at the end of the third game of the final set gave Federer the decisive edge.  
"On the big points, Roger showed again what qualities he has," Haas said. "I think I still played well and gave my best."  
Youzhny broke serve for a 2-0 lead in the first set and raced to a 4-0 advantage in the second before wrapping up the match 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.  
Although he owns five titles in Halle, where a street near the stadium is named Roger-Federer-Allee, the Swiss star last won here in 2008.  
"It's a big final for me, after that I'll start thinking about Wimbledon," Federer said.  
The defending champion at Wimbledon, Federer is looking to add to his record 17 Grand Slam titles.  
Federer blanked Mischa Zverev 6-0, 6-0 in the quarterfinals on Friday, and Haas provided his first challenge of the tournament. 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," Federer said. "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 wouldn't earn a break point again on Federer's serve. He's 3-11 against Federer throughout his career.  
Haas was No. 2 in the world in 2002. Hip surgery in 2010 left him at 896th. Unlike Federer, he already won a title this year, in Munich.