Serena Williams powered past Czech teenager Nicole Vaidisova 7-6 6-4 to reach the Australian Open final for the third time on Thursday.
The unseeded American, Melbourne Park champion in 2003 and 2005, edged a first set tiebreak and thwarted a late fightback from the 10th seed in the second to win through in an hour and 46 minutes on Rod Laver Arena.
Williams, the former world number one who stands at 81st in the rankings after a 2006 season blighted by injury, saved a set point in the ninth game of the first before wrapping up the tiebreak 7-5.
The 17-year-old Czech looked edgy after the setback of losing the first set, but recovered from 5-1 down in the second to give Williams a fright before the seven-times grand slam winner served out for victory on her sixth match point.
Williams will play top seed Maria Sharapova of Russia or Belgian Kim Clijsters, the fourth seed, in Saturday's final.