After three hours and 20 minutes on court, an exhausted Kvitova closed out a 6-7(10), 7-5, 6-4 win on her seventh match point.
"At the end I think there's no loser. I did everything today. I was fighting until the end."
Under the roof at the Optics Valley International Tennis Center, Kerber set the tone early on and broke Kvitova's serve in a 21-point marathon game, and kept the Czech firmly under pressure. But Kvitova pushed right back and wrestled a break back with the help of a pair of Kerber's unforced backhand errors.
Kerber dug herself out of a 2-4 deficit and saved set point at 6-5 to keep the pair on pace and send the opening set into the tiebreaker. Both players held a handful of set points during the decider, but it was Kvitova who blinked first, sending a pair of tired forehands long to let the World No.1 slip away with the set after an hour and twenty minutes.