Kvitova came out swinging and for most of the first set was hitting all her targets, firing 17 winners to just five unforced errors to take it, 6-2. Her game went awry in the second set, as she lost it at love - but the No.7-seeded Czech stormed out to a 4-0 lead in the third set and never looked back, missing out on her first three match points but finally closing out a 62 06 63 decision on the fourth match point.
And that last match point was a cracker - a 20-shot rally full of power and precision, Kvitova firing a huge crosscourt forehand on the 19th shot of the rally that the No.5-seeded Kerber netted on the 20th.
"In the first set I was attacking every ball and hitting so many winners but in the beginning of the second set I made some easy mistakes and felt slower in my legs, and that's what Angie was waiting for," Kvitova said. "I knew it wasn't over until the last point, though. After the second set I knew what I had to do - play the same way as the first set, stay aggressive and cut the mistakes down again.
"I'm very happy I could win this final today. For me the whole tournament was great - I felt good all week on the court. I really enjoyed my week here and it's even better to come away with the title."
Recovery was important for Kvitova in the final, too - a day earlier she scraped by a resurgent Venus Williams in an even tighter battle, edging the former World No.1 in a third set breaker, 36 63 76(2).
"Everyone has tight matches during a tournament - yesterday we played two and a half hours - but I still felt good today," she said. "I don't think the second set was because of yesterday's match."
Kvitova now has 11 WTA titles to her name - one in 2009 (Hobart), six in 2011 (Brisbane, Paris [Indoors], Madrid, Wimbledon, Linz and the WTA Championships), two in 2012 (Montréal and New Haven) and two in 2013 (Dubai and Tokyo). She is now an impressive 11-4 lifetime in WTA finals.
There's more good news for Kvitova. Having fallen out of the Top 10 after the US Open a few weeks ago - her first time out of the Top 10 since first breaking it May 9, 2011, which was 122 weeks before - she will now return to the elite, rising from her current ranking of No.11 in the world back up to No.7.
Kvitova and Kerber were playing the first all-lefty final on the WTA since Québec City in 2009 (where Melinda Czink beat Lucie Safarova for the title). It was also the the biggest all-lefty final since Paris [Indoors] in 1993 (where Martina Navratilova beat Monica Seles - read more about that one here).
Both of the Tokyo finalists will now head to Beijing for the Premier Mandatory-level China Open.
"I'll take a day off from tennis maybe," Kvitova said. "Then I'll think about my first match there."
Kerber was playing her second WTA final of the year - she was also a runner-up at the International-level event in Monterrey in April (to Anastasia Pavlyuchenkova). The German is now 2-5 in WTA finals.
"Petra was playing very well in the first set - in the second set I started to play my game, and I tried to do the same thing in the third set, but she started playing tougher again and moved better," Kerber said afterwards. "I was trying to give my best but she was better at the end, so all credit to her."