New York, Sep 8 (DPA) Roger Federer had to fight to maintain his flawless record over James Blake, beating the American for the fifth time with a 7-6 (9-7), 6-0, 6-7 (9-11), 6-4 win to advance into the semi-final of the US Open.

Federer, battling New York state-born Blake, was derailed Thursday as he served for victory in the third-set tiebreaker as well as in the fourth set.

Blake struggled to gain a little satisfaction as he lifted his career first set off the Swiss.

But the Federer style and power came to the fore at the end to get the job done as the world No. 1 moved to set up a semi-final clash with seventh seed Nikolay Davydenko.

Davydenko became the second Russian into the final four after a 4-6, 6-7 (3-7), 6-3, 6-4, 6-4 win over German Tommy Haas.

Federer flirted with a minor disaster in the tumultuous opening set that lasted more than an hour as Blake forced the Swiss to save three set points.

That mission accomplished, Federer put on a master class with a love second set and a break off Blake for 5-3 in the third.

But the American found a way to rally for a break-back and levelled at 5-all as the struggle for survival that characterized the encounter began to play out.

Blake fought like a wildcat to claw back, saving a Federer match point as the Swiss served for victory in the tiebreaker. Federer finally came through in four sets, thanks to seven breaks, 59 winners and a dose of courage.

The Swiss has now beaten 27-straight American opponents while Blake, a 2005 quarter-finalist, dropped to 1-8 against number 1 players.

"It was tough from both sides," said Federer, who is 29-4 at the Open and last lost at the event in the 2003 round of 16. "We played good tennis and it was great, even if the crowd was tough on me."

Blake admitted that the cheering masses were on his side: "Roger was playing against the whole crowd, and he did a great job."

Davydenko, who this year has taken off only one week in July from the nearly year-round tennis grind, joined compatriot and Davis Cup teammate Mikhail Youzhny in the final four.

"I could have lost in three sets," the winner said. "Haas played very well. He was serving great. I had no chance to break him early the match."

On Wednesday, Youzhny stunned second seed Rafael Nadal while Davydenko recovered from a two-set deficit after performing identical heroics in the fourth round of the Australian Open.

Bidding for his third final four at a major, Haas paid the physical toll in a third-straight five-set test.

Haas had lost seven-straight five-set matches coming into New York, but the 28-year-old began reversing his luck as he put out Robby Ginepri and Safin by going the distance.