Defending champion Andy Roddick recorded his first victory over Roger Federer since August 2003 to win the Kooyong Classic in Melbourne.
Roddick still has only one official win over Federer
The American beat the world number one 6-2 3-6 6-3, but he remains officially 1-12 against Federer because the match only counts as an exhibition.
Britain's Andy Murray finished third in the event after beating 2005 Australian Open champion Marat Safin 7-6 6-2.
The Australian Open kicks off at Melbourne Park on Monday.
World number six Roddick, 24, dominated early on the back of his powerful serve and broke Federer in the fifth and seventh games.
Switzerland's Federer rallied in the second set, breaking Roddick in the second game.
He missed two set points at 5-2 but won his next game to pull even, serving an ace at set point.
Federer wasted five break points in the third and fifth games of the third set before Roddick made the decisive break himself to lead 5-3.
He made no mistake serving out, firing back-to-back aces to claim two match points and clinching it when Federer put a backhand out.
"It really needs to be done on a big stage," Roddick said after the victory.
"But that said, it is nice, my game's going pretty well. I feel good going into the Open.
"My returns are working well and that will get me some looks at some breaks."
Despite the loss, and with only three matches this season behind him, Federer said he was happy with his preparation for the Australian Open.
"I'm feeling good - I feel like I'm ready," he said. "It's a shame I couldn't win but it was good preparation."