Halle, Germany, 18 June 2012 | AFP

Germany’s Tommy Haas has ambushed second seed Roger Federer 7-6(5) 6-4 to win the ATP grasscourt tournament at Halle in Germany on Sunday.

Playing in front of his home fans, the 34-year-old Haas added to his triumph three years ago to take his 13th ATP title.

Swiss great Federer, the second seed, was seeking a sixth win at the Wimbledon warm-up event having booked his seventh final ticket with a straight sets semifinal win over unseeded Russian Mikhail Youzhny.

Wildcard Haas, a former world No.2, secured his place in the climax with defeat of compatriot Philipp Kohlschreiber.

After claiming the title Haas said: “This has been one of the best weeks of my career, but I reckon I won’t really appreciate what’s happened until this evening.

“If someone had said to me beforehand that I was going to beat Roger Federer, probably the best player of all time, I would have thought they were mad!”

Federer was magnanimous in defeat, saying: “Tommy has performed well throughout, I’m thrilled for him.”

This was Haas’s third career win over Federer after beating his better-fancied rival at Halle in the semifinals in 2005 and 2006, against 10 defeats, the last in the semifinals at Wimbledon in 2009.

Federer broke to lead 3-1 in the opening set but proceeded to lose three successive games to find himself trailing 4-3.

Haas went on to clinch the set on a winning serve after 50 minutes.

In the second set Haas broke to lead 5-4 and serve for the match, winning out when Federer put a return long.