Andy Roddick aims to flush 40 months of frustration out of his system when he meets Roger Federer in the semi-finals of the Australian Open on Thursday.

Federer holds a commanding 12-1 record over Roddick, with his solitary victory achieved at the 2003 Montreal Masters, and the American is now fired up to end the losing steak.

"I feel like I'm in good form. I'd love to see where I match up," said the sixth seed.

"I feel like I'm hitting the ball well. I feel good going into the semis.I feel pretty confident with most of my game."

Roddick will draw comfort from his last two performances against the Swiss maestro.

He was one thunderbolt serve away from snapping his losing run at the season-ending Masters Cup in Shanghai last November as he held three match points in their round-robin match.

While that showing gave Roddick proof he once again possesses the weapons to trouble Federer, a win in the final of the Kooyong Classic invitational event 11 days ago would have boosted his confidence even further.

"For the past probably five or six months, the gap has either been closing a little bit or just he hasn't been extending it, which he's probably done the last three years or so. That's a good thing," said Roddick.

"I'm going to go in with a shot. I like going up and competing against him, I really do. I'm looking forward to the opportunity."

CLOSE MATCHES

Although the result in Kooyong does not count in the official records as it was an exhibition tournament, it has certainly given Federer some food for thought.

"We've had some really close matches," said the 25-year-old, who is targeting a 10th grand slam title. "We're about the same age. He's been number one, I don't think the record really plays much of a role.

"Now that we've played over 10 times, it always gets very interesting."

But ominously, Federer has sauntered into the last four without dropping a set and in the process penned yet another entry in the record books, becoming the first man in the professional era to reach 11 successive grand slam semi-finals.

Although Roddick has spent almost three hours more than Federer on court and dropped four sets in Melbourne Park, he feels such matches will have only made him more attuned to the task ahead.

"I don't feel like you can sit back and let him create. I think that's when you get in trouble," Roddick said.

"I'm going to have to go with what I do well and try to attack him, at least make him come up with shots from uncomfortable positions."