A relieved Roger Federer [Images] finally hit form at the US Open on Thursday as he shrugged off his first-week rust with a straight-sets quarter-final demolition of Argentine David Nalbandian.

"I was just particularly happy that I really played well," Federer said after his 6-2, 6-4, 6-1 win.

"The first round here was great. The next three were close matches. I wasn't happy to see that.

"I mean close, still straight sets some of them, but still I had the feeling they were tricky players. Especially against [Nicolas] Kiefer, I think I was really under pressure.

"So to come out and play a match again quite dominant is a great feeling, especially heading into the semis."

In the early part of his career, Federer struggled to cope with Nalbandian, who won their first five meetings.

The top seed went into Thursday's match having won their last two clashes, but said the memory of his early setbacks were still fresh in his mind.

"I felt I was a little tense going into the match because I knew the record I had against him," he said.

"But it's more just giving him a taste of what he gave me, in the beginning when we played. I kind of like that."

Lleyton Hewitt [Images], his semi-final opponent, won seven of his first nine matches with Federer, but the Swiss has won their last eight battles, including last year's final, which he won 6-0, 7-6, 6-0.

But Federer, who has now won 33 consecutive hard court matches and has lost just three times this year, said he still expected a tough battle against the Australian third seed.

"He knows he's not far away," Federer said.

"I know if I'm not on top of my game, I'm losing to Lleyton and he knows that. I expect a tough match."

Nalbandian, the 11th seed, who was the last man to beat Federer at the US Open, in the fourth round in 2003, said his serve had let him down.

"I couldn't win any free points with the serve," he said.

"I think he played much better than the other days.

"Federer today is one step up from the other guys. Always when you go out to the court you have a chance to win but when he's playing like this, it's very tough to beat him."

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