Germany's Tommy Haas became the first player into the final of the invitational Kooyong Classic with a 6-4, 6-4 victory over Argentina's Guillermo Coria in Melbourne on Thursday.
World number one Roger Federer, who was upset by Haas in three sets on Wednesday, bounced back quickly from that surprise defeat to overpower Ivan Ljubicic 6-4, 6-3.
Federer, who had said the loss to Hass would not upset his Australian Open preparations, took the first set after breaking the Croat's serve in the 10th game.
However, the Swiss dropped serve in the first game of the second set and was visibly annoyed with his lapse in concentration.
He broke back immediately and established a 3-1 lead before breaking Ljubicic again in the eighth game with a ferocious backhand pass.
Federer then held serve, clinching victory when Ljubicic sprayed a backhand return on a second serve over the baseline.
"It was a decent performance I guess today and I'm happy I won the match," Federer told reporters. "I couldn't be in better shape ... and I'm happy with the way I'm hitting the ball."
Federer said he is trying something different in every match at Kooyong to acclimatise to the conditions and test his game plan ahead of the year's first Grand Slam.
"I prefer this way [playing an invitational tournament] rather than having to work hard for a second week.
"It's like a practice so .... I try to play a bit more aggressive from the baseline, spin it more, slice it more, whatever it is I just like to try it."
But Federer said he tries not to stray too far from his game plan and would treat his game on Friday like a match.
DARK HORSE
Haas strengthened his case to be a dark horse at the Australian Open by seizing his chances in a baseline battle with Coria.
"I'm feeling pretty solid and winning the important points when I have to and that gives me confidence," he said. "I got broken a couple of times but when I needed to serve well I did."
Haas will meet either compatriot Nicolas Keifer or America's Andy Roddick, who play on Friday, in the final.
"You just try to go out there and work on things. It's perfect practice leading up to the Australian Open.
"Any time you work on your game and you leave the court a winner then you have a good feeling about yourself," he said.
World number five David Nalbandian withdrew from the tournament on Thursday after failing to shake off the effects of a viral infection.
Nalbandian retired in his opening match on Wednesday while trailing Germany's Nicolas Kiefer 6-3, 3-2, but expected to be fit in time for the Australian Open.
His place was taken by Max Miryni, who beat French teenager Gael Monfils 6-2, 7-5.
The eight-player tournament is one of the traditional warm-up events for the Australian Open, which starts in Melbourne on Monday.