Top seed Serena Williams beat fellow American Madison Keys 7-6(5), 6-2 to reach the Australian Open final on Thursday.
Williams will now face Maria Sharapova for the title after the Russian second seed beat compatriot Ekaterina Makarova earlier on Rod Laver Arena.
‘I had to dig deep mentally’
American Williams has won all five of her previous Melbourne Park finals, and while pushed by her clean-hitting compatriot on Thursday she was able to win the critical points to get out of trouble.
"She pushed me hard in the first set and I had to dig deep mentally to get through that," Williams said in a courtside interview. "I'm really excited to be in the final again. I didn't come here with that expectation so it's exciting."
Both players had entered the semi-final with injury and illness concerns, with Keys suffering a recurrence of an adductor injury, which ruled her out of Wimbledon last year, during her quarter-final victory over Williams' older sister Venus.
Williams was also battling a cough after a virus swept through the tournament.
‘I could have done a little more and been more aggressive’
Keys continued to demonstrate the clean power-hitting she has shown throughout the tournament, forcing the aggressive Williams behind the baseline and even breaking in the first game to get her first grand slam semi-final off to an explosive start.
However, Williams, bidding for a 19th grand slam title, got the match back on serve in the sixth game when she closed off Keys' options from the net and the 19-year-old sprayed her backhand wide.
Williams, 33, then produced several important serves in the tiebreak, including one down the centre line on set point to clinch it in 45 minutes.
Williams put pressure on Keys' serve in the second set, which resulted in two breaks of serve to give her a 5-1 lead, and while Keys saved seven match points in the seventh game and one more in the eighth, she could not stop her compatriot from advancing to the final against Sharapova.
"She came up with some great shots," Williams said of Keys' battle to prolong the match.
"I could have done a little more and been more aggressive, but that's a great sign that she played so well when she was down and didn't give up."
Sharapova screams her way into final
Maria Sharapova overcame some tricky wind conditions to advance to her fourth Australian Open final with a 6-3, 6-2 victory over Russian compatriot Ekaterina Makarova.
'I'm here and I'm pleased to be in the final'
"It's so special," the second seed said in a courtside interview.
"When you start off the tournament, you take it a match at the time and it was strange road, but I'm here and I'm pleased to be in the final".
Makarova had not dropped a set all tournament
Sharapova, who saved two match points in her second round clash with Alexandra Panova and has barely been troubled since, used her experience and powerful ground strokes to dominate an opponent playing in her first Australian Open semi-final.
Makarova, who also reached the last four at the 2014 US Open, had not dropped a set all tournament and her easy win over third seed Simona Halep in the quarter-finals gave her plenty of confidence going into the contest despite her 5-0 losing record against Sharapova.
She began strongly as Sharapova had trouble with her ball toss in the swirling wind, serving two double faults, and held two break points in an opening game that lasted 10 minutes before the five-time Grand Slam champion recovered.
Sharapova wrapped it with a strong service
The 27-year-old Sharapova immediately broke Makarova and then held to establish a 3-0 lead with the 10th seed yelling at herself as they went to the change of ends.
Makarova managed to break in the seventh game as Sharapova again had trouble with her ball toss before the second seed put her foot down and won eight of the next nine points to clinch the set in 48 minutes.
Sharapova refused to let up in the second set, while Makarova's serve faltered and forehand misfired as she failed to put any depth on her shots, allowing her compatriot to dictate the points.
The 26-year-old earned two more break points in the sixth game and finally forced Sharapova on the defensive but her forehand again let her down when the court was open and she lost yet another opportunity to get back into the match.
Sharapova then wrapped it with a strong service game to clinch her place in the final in 87 minutes.