Poland's Agnieszka Radwanska will put her eight-match winning streak on the line when she faces Dominika Cibulkova in the final of the Sydney International on Friday.
Top seed Radwanska needed seven match points on Thursday to down former winner Li Na and reach the final, remaining unbeaten in the early weeks of the new season ahead of next week's Australian Open Grand Slam.
Radwanska finally clinched a 6-3, 6-4 victory in one hour and 32 minutes over the Chinese star at the Ken Rosewall Arena.
Slovakia's Cibulkova became the first unseeded player in six years to reach the Sydney final when she ousted German second seed Angelique Kerber 6-2, 4-6, 6-3 in Thursday's other semi.
Cibulkova, who could reach as high as number 13 ranking from her current 14 if she wins the Sydney final, has not played Radwanska for five years and trails 3-0 in their encounters.
"But now it's a different story. It's a final," Cibulkova said.
"I haven't played her for a long time and she's a great player. She's playing a lot with her head. She's trying to use everything on the court.
"So let's see if my game is going to be good enough tomorrow."
Radwanska became the first top seed to reach the Sydney final since American Serena Williams three years ago.
She is in hot form ahead of the Australian Open after last week's victory in Auckland, where she beat Yanina Wickmayer to lift the trophy.
The top seed said her clutch of match points evoked memories of Auckland.
"It was kind of like a deja-vu from the Auckland final. I had also I think seven, eight match points before I win this final, so very similar situation," she said.
Radwanska said her constant new-season match schedule was not an issue heading into the Australian Open.
"Actually today when I was going on court, it was if I win, great; if not, it's not that big a deal because I really have had a lot of matches here and in Auckland," she said.
"I'm really ready for the Australian Open. But I always go on court to win.
I will do of course everything to win the final tomorrow as well, and we'll see. I wish to win 16 matches in a row (if she wins the Open)."
For Li, who won the title in Shenzhen last week, it was her first defeat in nine matches in the new season.
She fought hard against the Pole but errors at crucial times ultimately cost her the match.
The Chinese star, who won in Sydney two years ago, netted a drop shot from the baseline on set point and then lost the match with another netted drop shot.
"I was always feeling like I had a chance. Even the chair umpire didn't say finish, (so) everyone has the chance," Li said.
Li was satisfied with her week's work after a tough playing schedule at the onset of the new year.
"I made the semis. Why should I be sad?" she said. "It's my first loss for this year so it's a pretty good experience, right?"