The No.7-seeded Kvitova was the first to advance, ending the re-breakthrough run of Venus Williams in a nail-biter, 36 63 76(2). The two put on a serving display, each holding 13 of 15 service games in the match, but at the end of the day it came down to a third set tie-break, where Kvitova dominated.
"The whole match was very close - it was only about a few points in the end," Kvitova said afterwards. "I had a good start to the tie-break and I think every point in that tie-break was really important.
"Venus was a very tough opponent today. I knew she was playing very well here, and for her it's great to have this many matches. She missed some tournaments this year and it's important to stay healthy and play a lot. If she keeps this up she can be one of the players who can win Grand Slams."
Williams had revived her season - and career, really - with some vintage form during the week, taking out two of the hottest players of the year en route to the semis, namely No.2 seed Victoria Azarenka and No.13 seed Simona Halep. And while this run is over, it could be the start of something big.
"Coming into tournaments you never know how it's going to turn out, but I played a lot of great matches here," Williams said. "Today didn't turn out the way I wanted it to, but she played very well today, and a lot of it came down to match play too - she was hitting a lot of unreturnable shots in the tie-break.
"As I get into these positions more I'll start to convert - just a few painful misses today."
The No.5-seeded Kerber followed Kvitova into the final with a 64 76(5) win over No.4-seeded Caroline Wozniacki, holding off a late surge in the first set - she watched a 5-1 lead become 5-4 before closing it out - and battling back from 4-2 down in the second set to prevail in straight sets. She held off another late surge in the second set tie-break, watching 6-2 become 6-5 before finally closing the match out.
"The match was very close, and it's always tough to play a very close friend, but I've been playing very well this whole week and I'm really happy to be in the finals here for the first time," Kerber said after the match. "I have good memories of the semifinals here last year and I'm excited for tomorrow now."
"I'll take a lot of positives with me from this week," Wozniacki said. "I was fighting out there as hard as I could, not just today but throughout the whole week, and I just came up a little bit short today. But I have a lot of things to work on for next week in Beijing now - we have another big week ahead."
It will be the first all-lefty WTA final since Québec City in 2009 (Melinda Czink beat Lucie Safarova) and the first all-lefty Premier final since Paris [Indoors] in 1993 (Martina Navratilova beat Monica Seles).
"It can be difficult to play lefties, but Petra and I have played so much against each other that I don't think it will make a difference," Kerber said. "She's played well this whole week and I just have to focus on my game and focus from point to point, and stay aggressive. We'll see how it goes tomorrow."