The Bulgarian world No. 107 took advantage of the fast courts and what she described as an improved attitude to make surprisingly light work of the world No. 6 in a 6-4, 6-3 win.
Pironkova's ranking has been as high as No. 31 in the world but she said her mixed results were more an issue of attitude than injury issues.
"No, no injuries whatsoever. I'm very grateful for that actually, that I've been healthy," she said.
"I guess it's just my personality. It's a bit difficult for me to get motivated all the time. But I've been working very hard on that. I really hope that this season I could be more consistent."
Tellingly Pironkova tends to have strong results on faster courts, having made a semi-final and quarter-final at Wimbledon.
And players at Sydney Olympic Park have expressed surprise during the week at just how quickly these courts have been playing.
"I also think the courts are a little bit faster maybe from the previous years. But for me, that is only a plus. I usually play better when the game is faster," she said.
Kerber also enjoyed a straightforward route to the final with a 6-4, 6-2 win over American Madison Keys.
The German world No. 9 will be eyeing off her fourth WTA and a solid launchpad into the Australian Open where she had her best result last year in reaching the fourth round.
The pair have split the two WTA matches they have played, Pironkova taking out their last clash in Doha two years ago.